Here’s a great quote from Thomas Kempis’ Imitation of Christ, “Wherefore if you see another sin openly or commit a serious crime, do not consider yourself better, for you do not know how long you can remain in good estate. All men are frail, but you must admit that none is more frail than yourself.”
Kempis is not saying that we should excuse sin and other’s sinfulness, but rather we should not look down on sinners. For we ourselves are no better than they. Apart from Christ we are nothing. We should love them in spite of their sin and in so doing it is possible they will come to know the love of Christ. It should be that we would point the finger more at ourselves rather than at others.