The state of the soul in mortal sin, based on the analogy with bodily death. Just as a physical body may be not only ill or suffer injury, but cease to retain its principle of life, so the soul can lose sanctifying grace through mortal sin and supernaturally cease to live. It is, therefore, spiritually dead because it is no longer united with God, who gives it supernatural life, even as a body is dead on separation from its animating principle, which is the soul. While still on earth, this union with God is both a possession and a movement. We possess him by grace and in faith, and we are moving toward him in the beatific vision of glory. When persons sin mortally, they are twice dead: once because they lose the gift of divine life they formerly had, and once again because they are no longer moving toward the consummation of that life in heaven.
Mortal sins are no longer remissible by any power within the soul itself, much as the human body, once dead, cannot be brought back to life except by a special intervention of God. In Patristic literature the restoration is compared with the resuscitation of Lazarus. The exercise of almighty power in either case is the same. "Everyone who sins, dies," says St. Augustine. Only the Lord, "by his great grace and great mercy raises souls to life again, that we may not die eternally" (In Joannis Evangelium,49). Only infinite mercy can reconcile the grave sinner.