A human being is an entity compounded of spirit and matter. After death, the body becomes a decomposing corpse, whereas the spirit continues to live. The death of a human being does not mean his obliteration. Rather, he continues to live in the domain of the Barzakh (1) until the Resurrection takes place. In regard to the degrees of the creation of man, the Quran refers to the final stage of existentiation, when the spirit is cast into the body, in the following words:
Then We produced it as another creation. (Sura al-Muminun, XXIII:14)
Several verses allude to life in the world of the Barzakh; for example:
Behind them is a barrier (barzakh) until the day when they are raised up. (Sura al-Muminun, XXIII:100)
There are many more such verses that testify to the reality of life in the Barzakh.
(1). barzakh: the intermediary domain, ‘barrier’, or ‘isthmus’ between this world and the domain of Heaven and Hell.
Reference:
Ayatollah Jafar Sobhani, Doctrines of Shii Islam, A Compendium of Imami Beliefs and Practices, Translated and Edited by Reza Shah-Kazemi, published by I.B.Tauris Publishers, london • new york 2003
source : hawzahnews.com