The necessity of repentance as the essential condition for the sinner obtaining God's forgiveness is plainly taught both in the Jewish and Christian dispensations.

Prophets and penitents throughout the Old Testament bear evidence to this truth. The words of the Psalms of David, the exhortations of Jeremias and Isaias to the people of God to be converted, have become household words in our books of piety, exciting the soul in sin to arise and go to the God of mercy.

The New Dispensation was ushered in by the Forerunner of Christ preaching the Gospel of Repentance: "Do penance, for the kingdom of God is at hand." Our Lord announces His own mission to be to call sinners to repentance: "Unless you all do penance, you shall all likewise perish." He sent His Apostles that "penance and remission of sin should be preached in His name among all nations." And, while on earth, Jesus sent them, two and two, to preach that "men should do penance."

And, after the ascension of the "Saviour whom God hath exalted with His right hand to give penitence to Israel, and remission of sins,"[10] the Apostles proclaimed the same truth. Peter's very first sermon is: "Do penance and be baptized, every one of you."[11] He, on the occasion of the cure of the lame man, preaches: "Be penitent and be converted, that your sins may be blotted out."[12] The same Apostle writes: "The Lord beareth patiently for your sake, not willing that any should perish, but that all should return to penance."[13] St. Paul, in like manner. "God commandeth all men, everywhere, to do penance."[14] And again: "The benignity of God leadeth thee to penance."[15]

This contrition or repentance does not mean a mere cessation from wrong doing, and starting anew in the way of goodness, drowning in the past the evil done. On the contrary, as by sin we turned our backs on God to go into a far-off country, to spend there our substance, so by contrition must we turn main, retrace our steps, and journey to that Father and home whence we departed. Hence is the process named conversion to God, just as sin is defined to be an aversion from God. Moses, expressing this thought, says: "When thou shalt be touched with the repentance of thy heart, and return to Him, the Lord thy God will have mercy on thee."[16] And still more explicitly does the prophet Joel declare: "Be converted to Me with all your heart, in fasting, and in weeping, and in mourning; and rend your hearts, and not your garments, and turn to the Lord your God: for He is gracious and merciful, patient and rich in mercy."[17] Again, the inspired Word says: "Cast away from you all your transgressions, by which you have transgressed, and make to yourselves a new heart and a new spirit; and why will you die, O house of Israel?"[18]

The Lord God, whom we have outraged by sin, knows no past. "I am who am," is His name. In His holy sight, we who have sinned, and our transgressions, are ever abominable, unless we make to ourselves a new heart and a new spirit. "Be converted to Me, and I will be converted to thee," are the words of Him who exercises on us His great mercy.

Holy Church, in her General Council assembled at Trent, defined this contrition or repentance to be "a sorrow of mind, and a detestation of sin committed, together with a determination of not sinning for the future"—"animi dolor, ac detestatio de peccato commisso, cum proposito non peccandi de catero."[19] Or, as the same Council says: "Penitence was indeed at all times necessary for all men who had defiled themselves with any mortal sin, in order to the obtaining grace and justice, * * * that so, their perverseness being laid aside and amended, they might, with hatred of sin and a pious grief of mind, detest so great an offence of God."[20] And, as the Roman Catechism explains, this means no mere feeling, but a genuine act of the will. A mother may show more sensible signs of grief at the loss of her only child than when sorrowing for sin, yet this is not in the least inconsistent with the most perfect contrition or repentance.

There are times when the intense sorrow for sin arouses the whole being of man: exciting not only the higher, but also the lower and sensitive part of his nature. St. Mary Magdalen, David, and many other great penitents, wept bitter tears of sorrow for their past wrongs. This, though a heavenly favor, is no necessary part of repentance. Indeed, it is possible to weep and to have sensible sorrow without having a contrite heart. The three essential elements in contrition are: hatred of past sin, grief at having sinned, and a determined purpose at all costs to avoid, in the future, sin and the occasions of sin. These emanate from the will of man, not from the feelings; they must be strong or intense enough to make the sinner prefer to endure any evil, or sacrifice any good, rather than again offend God, so infinitely good in Himself, and so infinitely good to man.

Unhappily, it is within our power to hate, to grieve, and to purpose amendment very sincerely, and yet not have that sorrow which fulfills God's condition for the pardon of sin. Some human motive—such as loss of health or wealth, injury to reputation and influence, the ignominy and servitude of wrong-doing—may lead a man to detestation of the past and to a firm resolve to avoid wrong in the future. Excellent as may be such a change of mind, yet it is not sufficient to obtain forgiveness from on high. It is based entirely on the injury and loss accruing to self. God is excluded from the whole idea; and yet it is against Him, and against Him alone, that we have sinned.

The only sorrow acceptable to God is that which springs from a supernatural motive, the soul excited thereto by divine grace. In this is our utter helplessness shown; for while it is within our own power to do wrong, we cannot return to the path of duty and repent without the help of God. It is by the heavenly gift of grace operating within, and by the co-operation of the sinner, that the heart is made contrite. The remembrance of God's infinite love and perfections, accompanied by earnest prayer for mercy, may rouse the soul to hatred and grief for its sin, and thus is generated that contrition perfect through charity for having offended God so sovereignly good, who is to be loved above all things. For His own sake, and regardless of the penal consequences of sin, the soul is touched with sincere compunction. This sorrow, with the implicit or explicit desire to have recourse to the Sacrament of Penance, reconciles the soul at once with God, and restores the justifying or habitual grace lost by grievous sin. "There is now no condemnation to those who are in Christ Jesus, who walls not according to the flesh, but after the spirit. For the law of the spirit of life iii Christ Jesus hath delivered me from the law of sin and of death."[21] The soul about to go before God's judgment-seat, if it be in deadly sin, and have not at hand the means for obtaining absolution, is obliged to have this perfect contrition, or otherwise the sin remains unforgiven.

Again, the soul, contemplating in the sight of God the turpitude of sin, as made known to us by revelation, or the terror of God's judgment on those condemned to hell, or the irreparable loss of the sight of God consequent on sin, may be excited by fear of Him who hath power to cast into everlasting prison. The soul, awe-stricken by the painful sight of its own guilt, and by the sense of the judgment of God, yet hoping for pardon and resolved to sin no more, makes an initial act of the love of God, and appeals to His goodness for forgiveness. Though the motive is less perfect, yet "He who desireth not the death of the sinner, but that he be converted and live" does in His exceeding mercy accept this as sufficient for pardon, if there be added to it the actual reception of the Sacrament of Penance. In other words, in this case, unless the sinner shows himself to the authorized minister of reconciliation and receives his absolution, there is no pardon.

Whether this sorrow be of the perfect kind, arising purely from love of God, or whether it be less perfect, caused by fear of God: in either case, it is internal, seated in the mind and heart; it is supernatural in its motive, and springs from grace; it is universal, extending to every deadly sin committed; it is sovereign, displeasing the will more than any ill which could happen. "The sorrow which is according to God worketh penance unto salvation which is lasting: but the sorrow of the world worketh death. For behold this selfsame thing that you were made sorrowful according to God, how great carefulness doth it work: in you; yea defence, yea indignation, yea fear, yea desire, yea zeal, yea revenge."[22] This, then, is contrition: the first and necessary condition for the pardon of sin. It is begun and perfected in the soul by the impulse and by the assistance of the Holy Ghost. The grace of God, obtained through the precious blood of Jesus Christ, commences and completes the work of repentance. God, who is rich in mercy, through His exceeding charity with which He loved us, even when we were dead in sins, hath quickened as together in Christ, by whose grace you are saved.[23] "The blood of Jesus cleanseth us from all sin."[24] "We have redemption through His blood, the remission of sins, according to the riches of His grace."[25]