Answer: Intercession in Islam has two aspects: ontological intercession and legislative intercession.

1. Ontological Intercession: This type of intercession refers to the mediation of existential causes between God and other entities. In this context, all existential causes and effects act as mediators in the creation system, serving as intercessors. This form of intercession is based on causal relationships according to the laws of creation and primarily has a natural and ontological aspect.
2. Legislative Intercession: Legislative intercession is divided into two parts:
   • Intercession in the World: In this category, there are certain factors that lead to forgiveness, mercy, and divine proximity. Elements such as repentance, the Quran, faith, and righteous deeds, as well as angels and true believers, can act as intercessors in the world, facilitating forgiveness and mercy for sins.
   • Intercession in the Hereafter: In the afterlife, intercession becomes particularly significant during the Day of Judgment. Based on verse 143 of Surah Al-Baqarah, the martyrs are considered witnesses of human actions. These witnesses are not only those who have died in God’s path but also those who have witnessed the deeds of others and may testify on their behalf in the hereafter.

In both types of intercession, the key point is the permission and decree of God. This permission and intercession reflect the vastness of God's mercy and His boundless generosity.

According to the authentic hadiths the followings are the intercessors:

1. The Holy Prophet Muhammad (peace be upon him & his progeny): In a narration from Ja'far al-Sadiq, it was asked: "Do believers need the intercession of Muhammad (peace be upon him & his progeny), on that day?" He replied: "Yes, believers also have faults and sins, and there is no one who does not need the intercession of Muhammad, peace be upon him & his progeny, on that day."
2. The holy Quran: ImamAli ibn Abi Talib says in Nahj al-Balagha: "The Quran is an intercessor whose intercession is accepted."
3. The holy Ahlul Bayt: It has been narrated from Muhammad Baqir and Ja'far Sadiq that they said: "By God, we do intercede; by God, we intercede for our sinful Shiites such that our enemies, upon seeing it, will say: 'We have neither intercessors nor a kind friend.'"
4. Intercession of the Divine Prophets: Ali ibn Abi Talib on this matter says: "Heed the call of God's prophets, bow your heads before them, and follow their commands, so you may receive their intercession."
5. Intercession of Angels: From the Prophet of Islam, it is transmitted that he said: "Intercession is exclusive to prophets, successors, believers, and angels."
6. Intercession of the Martyrs of Truth: The Prophet of Islam regarding the intercession of martyrs has said: "One of them intercedes for seventy thousand people from their family and neighbours."
7. Intercession of Scholars and Religious Learned: The Prophet of Islam regarding this matter has stated: "One of them intercedes for seventy thousand people from their family and neighbours."
8. Intercession of the Believers: Imam Sadiq about the intercession of believers has said: "Believers are of two kinds: a believer who fulfils the covenant with God, as God Almighty says, 'There are men who have fulfilled what they pledged to God.' Such a believer is not afflicted by the horrors of this world or the hereafter. He is among those who intercede and does not need anyone's intercession; the second type is a believer who, like a plant stalk, bends this way and that. Such a believer is subject to the horrors of this world and the hereafter and is among those for whom intercession is made, but he does not have the power to intercede."
9. Intercession of Relatives: Imam Muhammad Baqir (AS) has said: "A person intercedes for his tribe; a person intercedes for his family; a person intercedes based on his deeds for two others; this is that praiseworthy station."
10. Intercession of Devotees: It is transmitted from Imam Ja'far Sadiq that he said: "When the Day of Judgment comes… it will be said to the devout: 'Go to Paradise.' And to the learned: 'Stand still and, because you have taught people good manners and education, intercede for them.'"

Brief Answer: Turning to God's chosen ones like holy Prophet or Imam Ali does not mean that Shias independently seek the resolution of problems from them. Instead, they seek their intercession so that they may advocate for us before God, seeking solutions from the Almighty. They strongly, believe that if these venerable figures do anything, it is by God's permission.

Believers in prayer and intercession do not consider these dignitaries as partners with God. Instead, they regard them as intercessors at God's threshold. For example, the powers attributed to Jesus Christ in verse 110 of Surah Al-Ma'ida, including reviving the dead and healing the sick, were all by the permission of God.

Detailed Answer: The verse in Surah Ar-Ra'd (13:14) states: "To Him belongs the true call. Those they call upon besides Him do not respond to them with anything, except as one who stretches his hands towards water to reach his mouth, but it will not reach it. And the supplication of the disbelievers is only in error." 

This verse metaphorically discusses "intercession" and "prayer," teaching people to whom they should stretch their hands. It then provides a parable for those who turn to the doors of creatures instead of the Creator.

Interpretation of the Verse: "There is no one to call upon besides Him" — Scholars differ on what "the call of truth" (Da'wat al-Haq) refers to. Some say it refers to monotheism, exclusive to God. Others believe it points to the Qur'an as the divine book. Many interpret it as "true prayer," meaning that if servants want their prayers answered, they should turn to God alone, as He is the only one capable of resolving problems and answering prayers. This interpretation is supported by the subsequent phrase in the verse, indicating that the prayers of the disbelievers are misguided because they turn to those who cannot defend themselves or benefit others.

"Do those who call upon others besides Him answer them?" — This part illustrates that those who petition others apart from God will not have their prayers answered. The metaphor of someone stretching his hands towards water to drink, but unable to reach it, emphasizes the futility of such prayers.

Thus, for solving our problems, we should not turn to anyone other than God. We must approach the magnificent threshold of God alone, for He is the Creator, the Sustainer, the Giver of life and death. He is the solver of all problems, and everything is in His hands. All others are needy, and He is the Self-Sufficient; all are weak, and He is the Absolute Powerful.

Answer: This type of intercession and prayer is not considered polytheistic. Turning to these esteemed figures does not mean we independently seek solutions from them. Instead, we reach out for their intercession so they may advocate for us with God, who is the ultimate solver of issues, under His permission. However, some accuse us of polytheism for these practices, misunderstanding the true nature of shirk and intercession in Shia belief.

Believers in prayer and intercession do not see these figures as God's partners but as intercessors at God's threshold. As stated in the Qur'an about Jesus Christ, all acts attributed to him, like reviving the dead or creating birds from clay, were performed with God's permission.

Thus, Shia belief holds that religious dignitaries can perform tasks that others cannot, by God's command, and can serve as mediators between people and God to resolve issues. Therefore, Shia intercession is neither shirk nor disbelief.

Furthermore, this discussion clarifies that prophets' miracles could be performed by the prophets themselves, by God's permission, such as Prophet Muhammad (peace be upon him & his progeny) splitting the moon. This is entirely plausible.

Brief Answer: The term "du'a" appears in the Quran with different meanings: 1. Du'a as "worship," as in Surah Jinn (18): "So do not invoke anyone along with Allah." Every Muslim knows that in this sense, du'a is exclusively for God. 2. Du'a as "calling" towards something, as seen in the command to the Prophet Muhammad (PBUH) in the Quran: "Invite to the way of your Lord with wisdom and good instruction." It's clear that this type of call is synonymous with faith.

1. Du'a as "requesting a need," which can be normal, like when witnesses are called to testify, they should not refuse. This type of call in normal affairs surely does not render one a disbeliever if they perform it. Sometimes it is supernatural, and this can be of two types: one with the belief in the independent effect of other than God, which is shirk because only God is independent in effect. However, the second type, while acknowledging that God is the cause of causes, involves seeking the intercession of the friends of Allah to ask God for something on one's behalf.

The Quran explicitly states: "The Children of Israel came to Moses and asked him to pray to God to provide them with various foods besides manna and quails." Moses did not reproach them for calling him instead of directly asking God themselves, nor did he accuse them of polytheism or disbelief. Instead, he made the request to God, and it was granted.

Detailed Answer: Among the concepts that some extremists misinterpret, leading to declarations of disbelief against many Muslims, is the understanding of "du'a" in the Quran. They believe that anyone who calls upon the Prophet Muhammad (PBUH) or any of the righteous as an act of worship is committing polytheism and their life and property become forfeit.

This misinterpretation is based on a narrow reading of certain Quranic verses without considering the diverse usage of "du'a" across the Quran:

1. "Du'a" as worship, such as in Surah Jinn (18): "Do not invoke anyone along with Allah." This refers to not equating or associating anyone in the acts exclusive to God, such as worship.
2. "Du'a" as calling or inviting to something, which is evident in the Quran's instruction to the Prophet Muhammad (PBUH) to invite people to God's way with wisdom and good teaching.
3. "Du'a" as requesting needs, which can be through ordinary means like requesting a witness to testify, and does not result in disbelief if performed.

Sometimes, "du'a" involves supernatural elements, such as seeking God's intervention through prayer. This type involves acknowledging that only God can affect change but using intermediaries (like prophets or righteous people) to ask God for help.

The harsh stance of some groups, which has led to violence and the declaration of other Muslims as disbelievers, stems from their flawed understanding of "du'a" in the Quran. They overlook the complexity and depth of Quranic teachings on prayer and supplication, leading to severe misjudgements and actions against many sincere Muslims.

Brief Answer: When it is practically impossible for humans not to seek help from sources other than God in their daily lives, it is evident that God's prohibition in seeking help doesn't mean seeking assistance from anyone or anything at all. Rather, it specifically addresses seeking help in a way that attributes independent causality to others besides God. The collective teachings of the Quran urge us to seek help and assistance through means and causes—both material and human—that recognize all help ultimately stems from God, not apart from Him. In other words, God is the true Helper and Protector, and any help from others originates from Him.

Seeking recourse to the Ahlul Bayt (the family of the Prophet) is among these divinely sanctioned means, allowed by God to seek closeness to Him and to ask for their intercession, and is not considered shirk. Seeking help from the Ahlul Bayt, if believed not to be independent in their influence, is not only permissible but also encouraged in verses like "And seek the means of approach to Him" (Quran 5:35).

Thus, according to the verse "Iyyaka na'budu wa iyyaka nasta'in," seeking help with the belief in the "independence of the helper" is shirk and contradicts the monotheistic principle of God's sole causality. However, seeking help through means prescribed by God, especially by valuing the position of righteous humans as a means to approach God, with the belief in their dependent causality, is emphasized in the Quran and is not shirk.

Detailed Answer: The verse "You alone we worship, and You alone we ask for help" from Surah Al-Fatiha (1:4) emphasizes monotheism in worship and seeking help. It denotes that seeking help, believing in the independence of the helper other than God, constitutes shirk and conflicts with the concept of Tawheed al-Af'aal (God as the sole cause of all effects). Why then do Shi'as seek help from their Imams and take recourse to them? Is this not shirk?

In response, it's important to clarify that seeking help from the Ahlul Bayt, akin to seeking help from one another or various means in the world, is permissible if it does not attribute independence in their influence. This issue can be further explained through several points:

1. Seeking help from other than God is unavoidable: One of the major issues with a literal interpretation of "Iyyaka na'budu wa iyyaka nasta'in" is the implication that all forms of assistance among humans and from different worldly means are forbidden, even utilizing one’s intellect or physical strength! Naturally, humans are created dependent on the world around them, including people, animals, inanimate objects, and celestial bodies. Would a Wise Creator issue a command contrary to the inherent nature of His creation?

2. If every use of material or human means was considered shirk, it would promote isolation and suspend social life requirements such as mutual aid, which is clearly not the intention of Islam. The Prophet Muhammad (PBUH) actively opposed this misconception and cautioned his companions against withdrawing from society under the misconception of avoiding shirk. Thus, it cannot be said that God's prohibition on seeking help from others extends to using means.

3. God commands cooperation in righteousness and piety: If seeking help from others without specific theological conditions were entirely forbidden, then why does God command in Quran 5:2 to help one another in righteousness and piety? Why, in Quran 18:95, did a godly figure ask for people's help in building a structure, and in Quran 8:72, Muslims are obligated to help each other?

These verses demonstrate that seeking help from material or human means, when done with the belief that these do not act independently of God's will, is permissible.

4. Some Quranic verses explicitly sanction seeking intercession and help through pious individuals: In addition to the verses that allow seeking help from means, some explicitly endorse the legitimacy of seeking intercession. For example, Quran 5:35 encourages believers to "seek means of approach to Him," which includes following the Prophet and the righteous, seeking their intercession, or swearing by their respected position (a form of venerating their status as a means of worshiping God).

In conclusion, while it's crucial to recognize that all effective power ultimately stems from God, seeking help through divinely appointed means, including the revered status of the Ahlul Bayt, aligns with Quranic teachings and does not constitute shirk. It is the belief in their absolute independence that would be problematic, not the act of seeking their intercession or help per Islamic doctrine.

Brief Answer: Quranic evidence shows a fundamental difference between the idolatry practiced by Prophet Noah's people and the legitimate practices of intercession and grave visitation among Shi'as. The idolaters in Noah's time actually worshiped their idols, considering them their "gods," which is clear from the term "gods" used in verse 23 of Surah Noah. A major mistake made by Wahhabis and other opponents of grave visitation is that they equate the seeking of intercession from saints, which is a request made in the spirit of monotheism and from God, with directly seeking favours from lifeless and senseless idols. None of those visiting the graves of Prophet Muhammad (PBUH) and the Immaculate Imams worship them.

Detailed Answer: Opponents of Shi'ism often attack the practice of visiting graves, branding it as a manifestation of polytheism and idolatry, even claiming that verses 23 and 24 of Surah Noah, which condemn idolatry, also apply to grave visitation.

Analysing the verses used in this accusation, verses 23 to 25 of Surah Noah address the idolatry of his people: "And said, 'Never leave your gods and never leave Wadd or Suwa' or Yaghuth and Ya'uq and Nasr. And they have misled many. And, [my Lord], do not increase the wrongdoers except in error.'" (Surah Noah, 23-25). 

According to some traditions, idolatry had not existed before Noah; it originated with his people when they started venerating statues of righteous men, which over generations led to the worship of these statues as gods themselves, a grave deception by the elite to manipulate and enslave the masses.

These historical and Quranic insights clearly demonstrate the significant difference between the idolatry of Noah's time and the practices of intercession and grave visitation among Shi'as. The latter involves no worship of the graves or the individuals therein; rather, it is an act of respect and seeking intercession, which is recognized as a request made to God through respected servants whose prayers are accepted by Him. Shi'as and other Muslims who practice this do not consider the physical site or the individual as divine and direct worship is solely towards God. This practice aligns with the Islamic teachings of monotheism, where any intercession is ultimately attributed to God's will and permission.

Brief Answer: Abrogation and bada' share the concept of the gradual manifestation of Divine will to His servants. The key difference is that abrogation pertains to legislative matters (e.g., the change of the Qiblah direction), while bada' pertains to existential matters (e.g., lifespan changes). Abrogation is accepted by all Muslims, where a law thought to be eternal might later be revoked by the Prophet (peace be upon him) and replaced with another, as historically noted in the change of the Qiblah. This is essentially a form of bada', though typically referred to as "abrogation" in legislative contexts and "bada'" in existential matters.

Detailed Answer: When discussing the meanings of "abrogation" and "bada'," it is crucial to understand that these two theological concepts have both similarities and distinctions. To understand these, we must first grasp the precise meanings of each term.

Meaning of Abrogation: Abrogation, linguistically, means to erase or remove something. In the Qur'an, this term is used in two senses:

1. Transcribing text from one copy to another, as seen in the context of recording actions in Surah Jathiya: "This is our book speaking unto you in truth. We were transcribing what you used to do."
2. The removal and cancellation of a religious ruling that appeared permanent, replaced by a subsequent decree. For example, initially, marriage to non-believers was permissible in early Islam, as Prophet Muhammad (peace be upon him & his progeny) married his adopted daughter Zainab to Abul-Ass before he accepted Islam, but this ruling was later abrogated.

Similarity between Abrogation and Bada': In bada', there is also a cancellation, but not of religious decrees; instead, it involves existential matters, indicating that God records a decree for a person based on their current state. If that person performs good deeds, like kinship ties or aiding the poor, God may change the original decree to a new one. This change is known to God from the outset, making it unknown only to us, not implying ignorance in God.

Opponents' Critique of Abrogation and Bada': Jewish beliefs, for instance, reject any change in decrees or laws, adhering to the notion that "God's hands are tied." This view similarly rejects abrogation in decrees, equating it to suggesting ignorance in God about the wisdom of decrees, which is considered impossible.

Argument against Opponents of Abrogation: Critics argue that if God changes a ruling, it either implies He was unaware of the underlying wisdom (implying ignorance) or that He knows it but decides to change, which contradicts divine omnipotence. We respond that while the notion of abrogation as discovering a mistake in earlier legislation implies ignorance and is unacceptable, abrogation in divine law is tied to specific times and circumstances known to God, who hides the end time from His servants. The previous decree was valid for its time but not meant to be eternal.

Distinctive Point of Abrogation and Bada': Thus, while both abrogation and bada' reflect the gradual manifestation of God's will, they apply differently: abrogation in legislative contexts and bada' in existential matters. Notably, scholars like Qadi Abdul Jabbar al-Mu'tazili and from Shi'a Islam, figures like Sheikh Mufid and Sheikh Saduq, see these concepts as parallel and compatible, underscoring the dynamic aspect of divine will in guiding humanity.

Brief Answer: "Taqiyya" refers to the concealment of one’s beliefs or religious practices out of fear of significant harm or to protect a crucial interest. 

The Quran states: "Believers should not take disbelievers as protectors instead of believers; whoever does this will not have a relationship with God, unless you do so to protect yourself from them." (Quran, 3:28)

The philosophy of "Taqiyya" is that when expressing true beliefs poses risks to one's life, honor, or wealth without any significant benefit, it is logical to preserve resources through "Taqiyya" for more critical situations.

Detailed Answer: "Taqiyya," linguistically means caution or safeguarding oneself and is variously defined as the concealment of one's beliefs or religious practices due to fear of harm or for another significant benefit, such as maintaining unity and avoiding conflict with common enemies. This concept has Quranic roots, illustrated by an incident involving a companion of the Prophet Muhammad (peace be upon him & his progeny), during a time when Muslims were a minority; it states: "Let not the believers take the disbelievers as allies rather than the believers. And whoever does that has nothing with Allah, except when taking precaution against them in prudence." (Quran, 3:28). This verse clearly addresses the issue of Taqiyya in the face of irrational enemies, leaving no room for negotiation.

The story of 'Ammar facing the polytheists, who forced him to utter words against Islam and the Prophet (peace be upon him & his progeny), is well-known. Under duress, he complied with their demands and later, tearfully fearing for his faith, approached the Prophet who reassured him that coerced statements do not harm one’s faith. This event led to the revelation: "Whoever disbelieves in Allah after his belief... except for one who is forced [to renounce his religion] while his heart is secure in faith." (Quran, 16:106). 

Additionally, the story of the believer from Pharaoh's people, who hid his faith and argued against the killing of Moses by saying, "Would you kill a man [merely] because he says, 'My Lord is Allah,' while he has brought you clear proofs from your Lord?" (Quran, 40:28) This narrative from the Quran praises the man's tactful concealment of his faith, indicating Divine approval of his Taqiyya. Islamic traditions are replete with references emphasizing the importance of Taqiyya, describing it as the believer's shield, which preserves them from enemies and conserves their strength for critical moments. Taqiyya is deemed part of faith, and a believer without Taqiyya is likened to a body without a head. It is considered one of the best deeds because it prevents the wasteful expenditure of energy. 

Moreover, Taqiyya serves a clear philosophical purpose: when openly expressing one's true beliefs could result in life-threatening danger without yielding substantial benefits, rationality dictates that one should not squander their energies frivolously but should preserve them through Taqiyya for more critical moments. Taqiyya is likened to a believer's armour, not a means to shirk responsibilities but a strategic tactic in warfare to protect one's forces from the enemy until the right moment for action.

Brief Answer: "Taqiyya" is categorised into two types:

1. "Taqiyya Khawfi" (fear-based Taqiyya), which involves concealing one's beliefs to avoid life-threatening danger, exemplified by stories such as the "Companions of the Cave" and "Ammar Yasir." 

2. "Taqiyya Mudarati" (conciliation-based Taqiyya), which means aligning with opponents not out of fear for one's life but for fostering greater unity and harmony. Practices such as joining Sunni community prayers, visiting their sick, and participating in their funeral processes are forms of "Taqiyya Mudarati" as recommended by Imam Jafar al-Sadiq (Peace be upon him).

Detailed Answer: "Taqiyya" is primarily divided into "Taqiyya Khawfi" and "Taqiyya Mudarati." "Taqiyya Khawfi" is the concealment of one’s religious beliefs due to fear of physical harm or life-threatening danger. This type is represented in the stories of "Mumin al-Fir'aun," "Ammar Yasir," and the "Companions of the Cave." On the other hand, "Taqiyya Mudarati" involves cooperation with adversaries in beliefs and actions not because of fear but to achieve greater unity and cohesion among communities. This type of Taqiyya is exercised when such an approach poses no threat to the practitioner but helps to avoid conflict and foster peaceful coexistence. For instance, despite known differences, Shi'ites participating in Sunni communal prayers in places like Saudi Arabia illustrates "Taqiyya Mudarati," promoting unity and reducing misunderstandings. This approach is underscored by practices and sayings from Imam Sadiq(Peace be upon him).who advised maintaining good relationships with the Sunni community by participating in their religious and social activities to exemplify the virtues taught by Imam Jafar al-Sadiq (Peace be upon him) and to dispel any misconceptions about the Shi'ite community.

Answer: Those among the Sunnis who criticize Shia for their belief in Bada' should note that this belief, in the same sense accepted by Shia, exists in their sources, including interpretations by Sunni scholars like Tabari, Qurtubi, and Ibn Kathir under verse 39 of Surah Ra'd -- "Allah erases what He wills and confirms, and with Him is the Mother of the Book." They quote the second caliph saying during his circumambulation of the Kaaba: "O Allah, if you have written me among the people of happiness, keep me in it, and if you have written me among the people of misery and sin, erase it and establish me among the people of happiness and forgiveness, for You erase and confirm, and with You is the Mother of the Book."

Erasing someone's name from the list of the miserable and adding it to the group of the blessed, manifesting a new divine will due to causes like prayers, is precisely Bada'.