The debate often arises: can i just forgive someone, or do they need to repent and ask for forgiveness? I believe the Bible is clear on this very thing: one must forgive when someone repents, and repentance (on their part) is the necessary condition (though not meritorious) for forgiveness. The best illustration is this: God forgives sinners WHEN they repent and believe.

Even more helpful than what I could write is this excerpt from a great pastor of a previous generation, John Angell James:

From “Forgiveness of Injuries” by John Angell James
2. Are we to forgive a person—if he will not confess his fault?
Forgiveness has various degrees, and in the fullest and most complete sense of the term it is not required of us, until confession is made. God does not forgive us unless we acknowledge our sins. “If we say we have no sin, we deceive ourselves, and the truth is not in us. If we confess our sins, he is faithful and just to forgive us our sins, and to cleanse us from all unrighteousness.” Christ makes the duty of forgiveness dependent upon the repentance of the offender. “If your brother sins, rebuke him, and if he repents, forgive him. And if he sins against you seven times in a day, and comes back to you seven times, saying, ‘I repent,’ you must forgive him.”

But still there are certain duties to be performed towards him even in this obdurate and unrelenting state of mind. We should in the exercise of meekness and gentleness endeavor to convince him of his wrong-doing in the manner laid down in the former essay. We are not, on discovering his impenitence and obduracy, at once to turn away from him in anger and disgust, and leave him to himself, and thus allow sin to lie upon him. And even after all suitable expostulations have been used, and he still remains stubbornly bent upon making no concession, we are not to allow ourselves to cherish enmity and malice towards him; we must harbor no ill-will towards him; we must pray for him—and be willing to do any good to him.
Kindness shown to an impenitent offender, in a way that will not seem to connive at his sin, or encourage a repetition of it—may melt his hard heart. This is what the apostle calls heaping coals of fire on his head, and by the agony of a guilty conscience, rendered more susceptible by your [kindness], melting down the cold, hard substance of his iron heart.

Here we act like God, who though he does not receive impenitent offenders to his favor, or bestow upon them the blessings of his children, still continues to them many providential comforts. And for what purpose? The apostle declares this, when he says, “Or do you despise the riches of His kindness, restraint, and patience—not recognizing that God’s kindness is intended to lead you to repentance?” This is extraordinarily beautiful—the goodness of God, instead of turning its back upon the unrepenting sinner and retiring from him in wrath and disgust, turns towards him its lovely countenance, and even takes hold of his hand to lead him to repentance.

Here is our pattern. We cannot receive the offender to our favor until he has confessed his fault; but we can be kind to him, and like our Heavenly Father take him by the hand and lead him to a better state of mind. He is not even in his sullen obduracy, to be an object of our hatred and revenge.

(the whole thing is found here at the Grace Gems website)

Thanks to my fellow elder, Jonathan, for finding this gem!
pdb