St. Alphonsus Liguori laid out five stages through which sin (if not resisted and repented of in its initial attacks) takes an increasing toll on the human person, making repentance less likely and more difficult.
While the names of the stages are mine, I am summarizing the insights of St. Alphonsus, who details these stages in his lengthy essay, “Considerations on the Eternal Maxims” (also called “Preparation for Death”) in Chapter 22, “On Evil Habits.” I have added some of my own additional insights as well.
The 5 Stages of Sin
Stage 1 – Impairment – The first effect of habitual sin is that it blinds the understanding. Scripture says, Their own malice blinded them (Wisdom 2:21). Yes, every sin produces blindness, and the more that sins are multiplied, the greater the blindness they produce.
A further effect of this blindness is a foolish and dangerous walking about. Scripture provides several references for this:
The wicked walk round about (Ps. 12:8).
They stagger as with strong drink, they reel in vision, they stumble in giving judgment (Is 28:7).
Behold, the wicked man conceives evil and is pregnant with mischief and gives birth to lies. He makes a pit, digging it out, and falls into the pit that he has made(Ps 7:14-15).
And thus habitual sin leads to impaired vision and an impaired walk. Not seeing, the wicked stumble about and fall into a pit that they themselves made.
Stage 2 – Indifference – After an evil habit is contracted, the sins that previously excited sorrow are now viewed with increasing indifference. Scripture says the following:
Fools destroy themselves because of their indifference (Prov 1:32).
But he who is careless of conduct will die (Prov 19:16).
And to the increasingly indifferent and careless, the Lord gives this solemn and salutary warning: In little more than a year you who feel secure will tremble; the grape harvest will fail, and the harvest of fruit will not come (Is 32:10).
And thus, as unrepented sin grows, not only does the sinner stagger about and fall into pits, he cares less and less about the foolishness of his ways. The sins that once caused shame, or the thought of which caused sorrow and aversion, are either unnoticed or seem normal—even attractive.
Stage 3 – Improbability – As sin deepens its hold, the willingness and even the capacity to repent decreases. Why is this? St. Augustine answers well when he says, dum servitur libidini, facta est consuetudo, et dum consuetudini non resistitur, facta est necessitas(when lust was served it became habit, and when habit was not resisted it became necessity) (Confessions, 8.5.10). Sin deepens its hold on the sinner in this way.
Stage 4 – Incorrigibility – As Scripture says, The wicked man, when he is come into the depths of sins, has contempt(Proverbs 18:3). St. John Chrysostom commented on this verse, saying that habitual sinners, being sunk in the abyss of darkness, despise corrections, sermons, censures, Hell, and God; they despise everything.
A bad habit hardens the heart and the habitual sinner remains increasingly unmoved and mired in contempt for any correction or remedy. Scripture says of them, At your rebuke O God of Jacob, they have all slumbered (Psalm 76:7). An evil habit gradually takes away all remorse and supplants it with angry indignation at any attempted correction.
And then it happens that, instead of regretting his sins, the sinner rejoices in them, even laughing and boasting of them. Scripture says, They are glad when they have done evil and rejoice in the perverseness of evil (Proverbs 2:14). A fool works mischief as if it were for sport (Proverbs 10:23).
Thus they are incorrigible. They laugh at attempted correction and celebrate their sins with pride.
Stage 5 – Indisposition – When the understanding is deprived of light and the heart is hardened, the sinner ordinarily dies obstinate in his sin. Scripture says, A hard heart shall fare ill at the end (Ecclesiastes 3:27).
Some may say that they will amend their ways before they die, but it’s very difficult for a habitual sinner, even in old age, to change his life. St. Bernard said, “The man on whom the weight of a bad habit presses, rises with difficulty.”
Indeed, how can a sinner, weakened and wounded by habitual sin, have the strength to rise? Even if he sees the way out, he often considers the remedies too severe, too difficult. Though conversion is not impossible, he is indisposed because it all seems like too much work. In addition, his love has likely grown cold for the good things that God offers.
And thus, even on their deathbeds, many sinners remain unmoved and unwilling to change; the darkness is deep, the heart is hardened, and sloth has solidified.
In these ways sin is like a progressive illness, a deepening disease; it moves through stages much as does cancer. Repentance at any stage is possible, but it becomes increasingly unlikely, especially by stage four, when the sinner becomes proud of his sin and joyful in his iniquity.
Beware the progressive illness of sin!