No Forgiveness
Rabbi Moshe Ben-Chaim
As Torah does not forgive a murderer—for he is killed—man too is not obligated to forgive one who murdered a loved one[1]. Torah does not ask man to act in a humanly impossible manner. Maimonides describes a limited scope of crimes for which we should forgive: “injury, cursing, robbery, and similar matters”[2]. Yet, there are graver matters for which one is not obliged or even capable to forgive, such matters that are dissimilar to those Maimonides outlines. As a murderer is not one whom man should forgive, sins graver than murder are certainly not subject to forgiveness:
The wise men said: “There are three transgressions which call forth retribution from the man who perpetrates in this world, and disinherit him from a share in the world to come. They are: idolatry, adultery, and bloodshed; but the evil tongue outweighs them all” (Arakin, 16b). The wise men, moreover, said, “He who speaks with an evil tongue is like an atheist, for it is said: “Who have said, Our tongues will we make mighty, our lips are with us, who is Lord over us?” (Psalms 12.5). (Maimonides Hil. Dayos 3:7)
[1] Rabbi Israel Chait
[2] Hilchos Teshuva 2:9