“This is the time of fulfillment. The kingdom of God is at hand. Repent, and believe in the Gospel!” (Mk 1:15) Repentance has always, from the beginning, been at the crux of the message of Jesus. To turn from sin is a necessary prerequisite to live as a Christian. But repentance goes deeper than this; true repentance results in a changed life.

Since repentance deals primarily with turning away from sin, it is important to discuss what exactly sin is. Any offense against God is a sin, but sins vary in gravity. John speaks of “sin which does not lead to death,” or venial sins, those which are not so serious as to cut us off from God. John also speaks of sins leading to death, which severely endanger our relationship with God, and lead unrepentant sinners into Hell.

When speaking about sins that can sever our relationship with God, it is important to distinguish between serious and mortal sins by examining the intention. A serious sin lacks the full consent of the will (for example, if one is under extreme stress, influence of drugs or alcohol, or fatigue) or proper understanding (e.g., a Catholic missing Mass on Sunday who was not catechized). On the other hand, a person committing a mortal sin fully comprehends that his actions will obliterate his relationship with God, but goes forward with the action nonetheless. While only this second type of sin completely deprives the soul of sanctifying grace, all sin, whether venial or grave, is to be taken seriously.

When we see someone committing a sin, it is important that we leave both justice and mercy in the hands of God, for we can neither condemn the person to Hell nor unlock for him the gates of Heaven.

We should primarily be concerned not with the sins of others but with our own, for “Why do you look at the speck that is in your brother's eye, but do not notice the log that is in your own eye?” (Matt 7:3). The first step towards repentance is acknowledging our own sinfulness. Consider two opposing examples from the Scriptures. Cain, after murdering his brother, was asked by God “where is your brother?” Rather than admitting his sin and begging forgiveness, Cain obstinately countered “Am I my brother’s keeper?” In contrast, when David was convicted by the preaching of Nathan about the exceeding sinfulness of his actions, he immediately turned to God and acknowledged his sin in prayer, saying, “I have sinned against the Lord.” The first of these men was cursed by God for his irrepentance, while the latter was immediately told by the prophet “the Lord has taken away your sin; you shall not die” (2 Sam 12:13). The lesson for us is that we should accuse ourselves now, lest on the last day we be accused by Satan. “State your transgressions first so that you may be justified” (Isa 43:26, LXX).

In dealing with our sins, we must be careful to be neither too lenient nor too scrupulous. Instead, we should make an honest examination of conscience. We are often convicted of our sins by the graces which God has implanted within our human nature. There are, however, some venial sins which we do by such routine habit that they escape the normal workings of even a well-formed conscience. Therefore when making an examination we need to reflect on more than just our “big” sins. It is important to take into account all the little things as well.

Consider these words of Thomas à Kempis’ Imitation of Christ:

In all these things we should pray for sorrow for having offended God, but this sorrow must never lead us to despair, for we have a sure hope in the grace of the sacrament of penance. This sacrament not only brings us forgiveness, it also helps us to form a correct conscience, resist future temptations, and amend our lives. Thus it is that much more important to frequently make a good confession.

A good confession is humble, sincere, and entire. Confession must never be a perfunctory exercise, a mere “laundry list” of sins, rather it must be the humble admission that we have willingly embraced evil rather than good. Obviously this should be convicting, but there is no guarantee that our emotions will be in line with our intellect. Therefore we prove our sincerity not by our feelings but by our actions, namely, by ceasing to commit the sins that we have confessed and by amending our lives.

But saying three Hail Marys is not enough. Such penances are not a bad practice, but they are not complete either. Rather this is a first step, taken in faith, to open yourself up to grace. These prayers help you to move towards God, to take action, and to come closer to a true conversion of heart. But after praying for this grace you must act on it. Often the first way to begin to amend your life is to make reparation to those whom you have offended, e.g., returning or replacing things you stole, telling the truth after having lied, or apologizing to someone you’ve insulted.

It is crucial after having confessed a sin to take practical steps to cut that sin out of your life. First and foremost we should remove the near occasions of sin, for example, turning off the TV when it seems something sketchy is afoot. In addition to avoiding sinful environments we should also take steps to practice the virtues contrary to our vices. For instance, someone prone to envy should practice generosity, and someone given to sloth should practice zeal, perhaps by volunteering for some worthy cause. A life that strives after holiness by avoiding sin and practicing virtue will culminate in perfect repentance.

Of course we can do none of this on our own, but only by the grace of God. When the book of Hebrews speaks of “repentance from dead works and of faith toward God” (6:1), it counsels us to reject not only sin but also self-justification. It is very easy even for earnest Christians to lapse into autopilot, merely going through the motions and, without realizing it, to begin to focus on self rather than on God. One can reach a point where doing the works of God takes the place of God. This spiritually empty process of ‘making yourself a better person’ or ‘making the world a better place’ is nothing but diverting your energy into the vain pursuit of a false holiness.

Having rejected all sin and self-justification, we must “bear fruits in keeping with repentance” (Lk 3:8). This has a profound impact on every aspect of our lives. We must live lives of faith, for “all that is not of faith is sin” (Rom 14:23). Every insignificant action, every mundane task, every routine chore must be offered up to God as a sacrifice for His glory. Saint Thérèse of Lisieux said that she would prove her love for Christ by “every little sacrifice, every glance and word.” This, then, is the fruit of repentance: “the doing of the least actions for love.”