I am motivated to forgive my ex-husband for the sake of the children. In other words, I do not want them to grow up hating their father. Is this a good reason for my forgiving him?
Yes, this is an excellent reason for forgiving. You want to protect your children and this is very honorable. You are not thinking of yourself, but of them and that, to me, is heroic. I think your children will benefit greatly from your decision to forgive and your actions of forgiving. I wish you the best with this.