The following is from A W Tozer's Renewed Day By Day, a daily devotional. I went through it several years ago. This devotion is from August 19 and is entitled: The Example of Jesus: Hold No Grudges
Then said Jesus, Father, Forgive them; for they know not what they do . . . . Luke 23:34
Jesus Christ left us an example for our daily conduct and from it there can be no appeal. He felt no bitter resentment and he held no grudge against anyone!
Even those who crucified Him were forgiven while they were in the act. Not a word did He utter against them nor against the ones who stirred them up to destroy him.
How evil they all were He knew better than any other man, but He maintained a charitable attitude toward them. They were only doing their duty, and even those who ordered them to their grisly task were unaware of the meaning of their act.
To Pilate, Jesus said, "Thou couldest have not power at all against me, except it were given thee from above." So he referred everything back to the will of God and rose above the swampland of personalities.
The person with the resentful heart takes just the opposite course, however. He grows every day harder and more acrimonious as he defends his reputation, his rights, his ministry, against his imagined foes!
The worst feature about this whole thing is that it does no good to call attention to it. The bitter heart is not likely to recognizes its own condition. The resentful man in the meantime will grow smaller and smaller trying to get bigger, and he will become more and more obscure trying to become known. As he pushes on toward his selfish goal his very prayers will be surly accusations against the Almighty and his whole relationship toward other Christians will be one of suspicion and distrust!