What Forgiveness Is
Jesus calls us to be like God in the showing of mercy "that you may be sons of your Father who is in heaven" (Matt. 5:45). So how does God forgive?
Scripture tells us that he "desires all men to be saved and to come to the knowledge of the truth" (1 Tim. 2:4) and the he is "not wishing that any should perish, but that all should reach repentance" (2 Pet. 3:9).
We should have the same attitude. We should will the good of every soul, even the most evil ones. No matter who they are or what theyve done, we need to will their ultimate good, which is salvation through repentance.
What if they dont repent?
One may hope that they were not culpable for their actions and so can be saved, that they were affected by mental disorder, intense pressure, ignorance, indoctrination, or something that affected their judgment so that they werent responsible for their actions at the time they committed them.
But what if they were?
We may hope that they are brought around to repentance. In fact, we ought to hope this even for those who werent responsible for their actions. But to be brought to repentance often requires suffering the consequences of ones sins.
This is where righteous anger comes in. It is often said that anger is a desire for vengeance (cf. ST II-II:158:1). This puts it a little more harshly than many today would want to say it, but anger does involve a desire that the offending person experience the consequences of his sins. Without this desire, the feeling would be something less than anger, such as simple frustration.
Anger is righteousin keeping with justiceif it is still fundamentally directed toward the good. Thus one may wish that a person experience the consequences of his offenses to sufficiently understand how he has hurt others, and teach him to not commit them in the future.
However, "if he desires the punishment of one who has not deserved it, or beyond his deserts, or again contrary to the order prescribed by law, or not for the due endnamely the maintaining of justice and the correction of faultsthen the desire of anger will be sinful" (ibid., 2).
It is so easy for us in our fallen state to slip into sinful anger that Scripture repeatedly warns us against it, but anger serves a fundamental purpose.
If a person with whom we are angry repents, then the obligation to forgive kicks in. This means that we must be willing to set aside our anger because he no longer deserves it. We may still feel it for a time, and it can even be advisable to let him know this in order to underscore the lesson he needs to have learned. But we do need to manage our emotions so that we let the anger go and, to the best of our ability, encourage it to fade.
And what if a person doesnt repent when all is said and done?
At some point we need to let our feeling of anger fade, not for his sake but for ours. It isnt good for us to stay angry, and it poses temptations to sin. Ultimately, we have to let go of the feeling of anger and move on with life. Frequently we have to do so even when a person has not repented.
But for the person himself, what should we hope? With regret, we recognize that it is appropriate that he gets what he chose, even if that was hell. This is, after all, the attitude taken by God toward those who choose death rather than life.