Although there are many situations where it would be immoral to discount the wrongness of an act, and many situations where it would be immoral to absolve a person of responsibility for a wrong act, I do not think that forgiveness can ever be immoral. This is because I view forgiveness as a matter of giving up on one's feelings of resentment towards someone else -- not a matter of giving up on one's judgment that that person is responsible for doing something that was wrong. Even if feelings of resentment are sometimes useful (for motivating change, for example), they are not sufficiently under one's control to make the loss of resentment immoral. More importantly, though, I do not think it is our feelings that make us moral or immoral so much as our intentions, and there is no guarantee that resentful feelings lead to moral intentions -- even when the resentment is directed towards the doing of a serious wrong.