Cardinal Manning explains that the fourth effect of mortal sin is that “the soul in itself begins to lose its vigour and its strength.”
Every human person “needs the help of nature and of grace: and the supernatural gifts of God—faith, hope, and charity—are by a mortal sin either entirely destroyed or weakened. Charity is utterly destroyed. Hope remains and faith remains, but hope begins to grow faint; for a man conscious of having sinned mortally against God cannot deceive himself with the hope of salvation unless he has grounds for hope; and what grounds can an impenitent sinner have?”
“‘There is no peace, saith my God, for the wicked’ (Is 48:22). . . . Faith shows him judgment to come, and the witnesses that will stand before the Throne on that day and bear testimony against him; and therefore the faith that remains in him is a terrible light, warning him and piercing his conscience. So far the supernatural grace that is still with him is goading him with fear to bring him back to God; more than this it cannot do.”
“The natural powers of the soul are also affected when a man is in a state of sin. The heart becomes corrupt, the soul becomes weak.” For example, “The man who indulges himself in drink loses the vigour and command of his will. The will becomes feeble and loses its imperious control. It can no longer command the man. It is like a rotten helm which the ship will not obey.”
The fifth effect of mortal sin is that “it brings a man into a double debt before God—it brings him into the debt of guilt, and into the debt of pain—and he will have to pay both. The debt of guilt he must answer at the Day of Judgment. The debt of pain he must suffer before he can see God, either here, or after death. . . . God has ordained it from the day in which He said: ‘In the day that thou eatest thereof, thou shalt die the death.’ From that day onward, no sin has ever been committed that has not been followed by its measure of judicial pain. It must be some day expiated, either by bearing it here or bearing it hereafter, or by a loving sorrow prevailing with God through the Precious Blood of Jesus Christ, to wash out from the book of His remembrance the great debt of accumulated sin.”
Quotations from Henry Edward Manning, Sin and Its Consequences, 2d ed. (London: Burns and Oates, 1874).