First, there are usually temptations, and we must overcome them through prayer. We should not pay attention to these resentments because the act of our will is sufficient. With our will, we should say, "With God's grace, I forgive the past in which I was offended," or in another case, whatever the offense may be. This is enough because we must not confuse our will with our feelings. Feelings may still be present, along with past traumas and wounds in the soul, but we are called to offer them with love, humility, and repentance to the Lord.
Even when we are unjustly injured or offended, we must offer these wounds for the atonement of our own sins, in obedience to the Lord, and to increase in us the love for all our enemies, just as He forgave on the cross. We are called to imitate Christ and strive to be true, faithful Catholics. This is, of course, a very demanding path, but it is a necessary one for Christian life in imitation of Christ.
