What is the truth about death? What are its stages? Does a person feel his death is imminent?

All perfect praise be to Allaah, The Lord of the Worlds.  I testify that there is none worthy of worship except Allaah, and that Muhammad, sallallaahu ‘alayhi wa sallam, is His slave and Messenger.

Allaah The Almighty created life and death; He Says (what means): {[He] who created death and life to test you [as to] which of you is best in deed - and He is the Exalted in Might, the Forgiving.}[Quran 67: 2] Death is when the soul comes out of the body and departs, whereas, life is the attachment of the soul to the body and its connection to it. This is the reality of life and death. However, on the Day of Judgment Allaah The Almighty will materialize death in the form of a ram. After that, the command will be given that it is to be slaughtered.

On the authority of Abu Sa‘eed Al-Khudri the Prophet, sallallaahu ‘alayhi wa sallam, said that  death will be brought forward in the shape of a black and white ram. Then a caller will call, 'O people of Paradise!' Thereupon they will stretch their necks and look carefully. The caller will say, 'Do you know this?' They will say, 'Yes, this is death.' By then all of them will have seen it. Then it will be slaughtered. After that, it will be announced again, 'O people of Hell!' They will stretch their necks and look carefully. The caller will say, 'Do you know this?' They will say, 'Yes, this is death.' And by then all of them will have seen it. Then it will be slaughtered and the caller will say, 'O people of Paradise! Eternity for you and no death. O people of Hell! Eternity for you and no death.'

After saying these words,  the Prophet, sallallaahu ‘alayhi wa sallam, recited the verse (which means): {And warn them, [O Muhammad], of the Day of Regret, when the matter will be concluded; and [yet], they are in [a state of] heedlessness, and they do not believe.}[Quran 19:39] [Al-Bukhari]

It is narrated that Ibn ‘Abbaas reported that Allaah The Almighty had created death in the form of a black and white ram that causes death to everything that it passes by in this world; and that He created life in the form of a horse that causes life to everything that it passes by; or that its scent reaches in this world. However, Al-’Uloosi stated that this idea is illogical and similar to Sufi eccentricities.

Death does not have any stages; when someone’s life term ends, he dies immediately.  Allaah The Almighty Says (what means): {So when their time has come, they will not remain behind an hour, nor will they precede [it].}[Quran 7:34]

Allaah The Almighty may actually inspire some people that their death is imminent. However, a person may have an illusion and think he is about to die while, in fact, he will not.

Allaah Knows best.