If you want to overcome the spirit of slander, blame not the person who falls but the prompting demon. No one wants to sin against God, even though all of us sin without being compelled to it.
I knew a man who sinned openly but repented in secret. I denounced him for being lecherous but he was chaste in the eyes of God, having propitiated Him by a genuine conversion.
Do not allow human respect to get in your way when you hear someone slandering his neighbor. Instead, say to him, "Brother, stop it! I do worse things every day, so how can I criticize him?" You accomplish two things when you say this. You heal yourself and you heal your neighbor with the one bandage.
St. John Climacus,
The Ladder of Divine Ascent, 10