Asserting that someone can independently do so without God’s assistance is in absolute contradiction with tawhid af’ali (oneness in action), for death and life is solely in God’s hand.
However, if one were to carry out this act with God’s consent, it would then be considered probable and possible.
As stated in the Quran, God mentions Jesus (A.S.) saying: “I can make see thee who has been born blind and I can cure leprosy and with God’s will, revive the dead.”
And since the Prophet of Islam, being the seal of Prophets, consists of a higher position and closer stance to Allah in relation to other Prophets including Prophet Jesus and in light of the Quran stating that Ali is the Prophet’s nafs (self), why would it seem improbable for the Prophet (sa) and Ali (as) to do what Prophet Jesus (as) did?
In order to present a complete and substantial explanation, we will analyze the said question from three different perspectives and subsequently answer the question.
1. Theoretical assessment of dhati (essential) possibility:
Fundamentally speaking, is it possible for someone who has been created and will inevitably face death himself to revive another human from death?
2. Assessment of Practical occurrence:
Assuming the logical possibility of such, will it ever happen in the real world?
3. Can Imam Ali (A.S.) revive the dead?
Theoretical assessment of dhati (essential) possibility of revival of dead:
This issue can be discussed from two angles;
A. Whether one can do so independently, regardless of God assisting him or not, which is in extreme contradiction with tawhid af’ali (oneness in action).
RegardingTawhid afali, the two qualities of granting death and life are part of the ten qualities restricted to God; creation, providence, giving life, casting death, independence, bringing poverty, invulnerability and honor, misery, health and sickness.
Given this, life and death are confined to God Almighty.
B. However, by God’s assertion and divine authority there is no logical impossibility in light of the fact that as long as something isn’t reasonably impossible, God, providing his limitless power, is capable of doing it. Under these circumstances, the true doer who is actually carrying out the act is God and the person performing the act is simply a medium in the process, similar to the role the angel Izrail plays in taking the lives of humans which is again truly God’s quality.
Without doubt the best proof that something can theoretically happen is it occurring in reality; for it has been said: “the best reason as to the possibility of something is its occurrence”. In regards to the matter at hand, if we can cite someone from God’s obedient servants that have performed such a thing then all doubts will vanish. As stated in the Quran, God mentions Jesus (A.S.) saying: “And (make him) a messenger to the children of Israel that: I have come to you with a sign from your Lord, that I determine for you out of dirt like the form of a bird, then I breathe into it and it becomes a bird with Allah's will and I heal the blind and the leprous, and bring the dead to life with Allah's permission and I inform you of what you should eat and what you should store in your houses; most surely there is a sign in this for you, if you are believers.” In keeping with this ayah, not a single Muslim should doubt the occurrence of such a matter.
But is Imam Ali (as) capable of bringing back to life a dead person?
According to the ayahs narrated above from the Quran; Ale-Emran 49 and Al-Maeda 110, Prophet Jesus (as) has definitely done so and since the Prophet of Islam, being the seal of Prophets, consists of a higher position and closer stance to Allah in relation to other Prophets including Prophet Jesus in addition to the Quran stating that Ali is the Prophet’s nafs (self), why would it seem improbable for the Prophet (sa) or Ali (as) to do what Prophet Jesus (as) did?! Although, one must keep in mind that this is merely an assessment of the possibility, with no implication of it actually occurring and taking place in reality. But we must also take into perspective that something not taking place does not prove inability. For example, if Prophet Jesus (as) never transformed a stick into a snake, this for sure does not indicate that he never had the power and authority to do so.
Therefore, why would it be inconsistent for an apostle of Allah (swt), such as Imam Ali (as) to revive the dead?
 Tayyeb, Seyed Abdul-Husein, Atyab al-Bayan fi Tafsir al-Quran, vol. 6, pg. 326, publisher: Entesharate Eslam, Tehran, second print, 1378 (solar calendar).
 Ale Imran:49; Ma’idah:110.
 Tabarsi, Fadl bin Hasan, translation of Majma’ul Bayan fi Tafsir al-Quran, vol. 3, pg. 101, publisher: Entesharate Farahani, Tehran, first print, 1360 (solar calendar).
 Ale Imran:61,“Should anyone argue with you concerning him, after the knowledge that has come to you, say," Come! Let us call our sons and your sons, our women and your women, our selves and your selves, then let us pray earnestly and call down Allah's curse upon the liars”(In this story, the prophet took Hasan and Husein as his sons, Lady Fatimah as his women and Ali as his self to perform mubahalah and the disbelievers surrendered).