According to Saint John of Damaskos, repentance is a return from the unnatural to the natural state and from the devil to God through ascesis and toil; moreover, it is a voluntary return from transgressions toward the opposite virtues. The signs of repentance are remorse and a change of mind, while characteristics of repentance include contrition of the heart, tears, the rejection of sin, and the love for virtue. Repentance must, of necessity, be sincere. It is sincere when accompanied by contrition of the heart, by the disposition to compensate Divine Rigtheousness, and to confess one’s sins.
True repentance is a change of mind for one’s actions, an alteration of one’s ethical life, a change toward the better, complete rejection of one’s previous life and sin, steadfast willingness to exercise virtue, complete unification of one’s own will with the Divine Will (i.e. the Divine Law). Therefore, repentance is an ethical rebirth of man and the starting point of a new, virtuous life.
A model for true repentance is given to us by the Prophet Isaiah who incites the Jews to repent and return to God. This is what he says: “Wash you, be clean; remove your iniquities from your souls before mine eyes; cease from your iniquities; learn to do well; diligently seek judgment, deliver him that is suffering wrong, plead for the orphan, and obtain justice for the widow. And come, let us reason together, saith the Lord: and though your sins be as purple, I will make them white as snow; and though they be as scarlet, I will make them white as wool” (Isa. 1:16-18).
He who truly repents has a broken and humbled heart. David, the prophet and king, is a true example of repentance. His mind and heart, soul and body, both the inner and outer man bear witness to his true change of mind and his burning desire to propitiate God. His Psalms, full of divine fervor – especially the Psalm of repentance (50) through which he seeks the mercy of the Lord – are translucent mirrors in which his heavenly zeal and the exalted character of true repentance are reflected. This type of broken and humbled heart God will not despise.
Similar examples are also the repentance of Manasseh, the king of Judah; the Ninevites; the publican; and that of the prodigal son. The repentance of Zacchaeus simultaneously indicates both the manner in which the cure of sin takes place and the manner in which the offended [Divine] Righteousness is compensated. “Behold, Lord, the half of my goods I give to the poor; and if I have taken anything from any man by false accusation, I restore him fourfold” (Lk. 19:8). The myrrh of the repentant harlot, the tears of Peter, and the repentance of the thief are most expressive examples of true repentance and, concurrently, of God’s love towards man.
False repentance is that exhibited by Pharaoh, who confessed his own sin ten times, asked for forgiveness ten times, received forgiveness ten times, enraged God ten times, and finally, marched out against God’s will. His foolish heart was not humbled by his sins, but remained hard and unyielding (cf. Ex. 10:16-20). His repentance was repentance due to fear, not repentance with feeling, not with consciousness of his sin. He repented out of fear of being punished or killed and not from the feeling that he sinned against God, not from the realization of his great sin. This is why he was submerged within the depths of the Red Sea, suffering rightly for his false repentance.