C.S. Lewis offers these words.

“To forgive the incessant provocations of daily life–to keep on forgiving the bossy mother-in-law, the bullying husband, the nagging wife, the selfish daughter, the deceitful son–how can we do it? Only, I think, by remembering where we stand, by meaning our words when we say in our prayers each night ‘Forgive us our trespasses as we forgive those that trespass against us.’ We are offered forgiveness on no other terms. To refuse it is to refuse God’s mercy for ourselves. There is no hint of exceptions and God means what he says” (C.S. Lewis, “he Weight of Glory” in The Quotable Lewis eds. Wayne Martindale and Jerry Root [Wheaton, IL: Tyndale House, 1989], 221).