"There will always be defects in ourselves or others which we cannot correct. These we must simply tolerate until God in His goodness sees fit to change things... 2. If once or twice you have warned someone and that person does not comply, do not contend further with such a one, but leave all in the hands of God, that His will be done and that He be glorified in all His servants, for He knows well how to turn evil into good... Learn how to be patient in enduring the faults of others, remembering that you yourself have many which others have to put up with. If you cannot make yourself be what you would like, how can you expect another to be as you would like? We wish to see perfection in others, but do not correct our own faults. We want to have others strictly reprimanded for their offenses, but we will not be reprimanded ourselves. 3. We are inclined to think the other person has too much liberty, but we ourselves will not put up with any restraint. There must be rules for everyone else, but we must be given free rein. It is seldom that we consider our neighbor equally with ourselves... 4. God wills us to learn to bear one another's burdens. No one is without faults, no one without a cross, no one self-sufficient and no one wise enough all alone. Therefore, we must support, comfort and assist one another in all charity. Adversity is the best test of virtue. The occasions of sin do not weaken anyone; on the contrary, they show that person's true worth."
St. Thomas a Kempis, The Imitation of Christ, book 1, chapter 16.