His body is still there, but the life has gone. Only the dead body is left. Man is not only a body. He also has a soul and spirit. It is hard for us to know the difference between soul and spirit because we cannot see them as we can see the body, but the Bible shows us that there is a difference.
Animals have a body and a soul, but they have no spirit.
A man has a body, a soul and a spirit. The soul is what makes the difference between a living being and a dead one, but the spirit is what makes the difference between a man and an animal. Because we have a spirit, we can have a close relationship with God. Our feelings and desires come from the soul. Our ability to know and think comes from the spirit.