Below is one of Jonathon Edwards resolutions. You can read them all here. You can read some about his story and how he wrote these at age 19 here.
Resolved, never to say anything at all against anybody, but when it is perfectly agreeable to the highest degree of Christian honor, and of love to mankind, agreeable to the lowest humility, and sense of my own faults and failings, and agreeable to the golden rule; often, when I have said anything against anyone, to bring it to, and try it strictly by the test of this Resolution.
We could spare ourselves and others a lot of grief if we followed this short resolution. Especially relevant is the phrase "a sense of my own faults and failings." If we faithfully immerse ourselves in and allow it to interpret us, we will be plenty aware of our own need for grace and more quick to extend it to others. As Jesus said,
Matthew 7:3–5 (ESV) Why do you see the speck that is in your brother’s eye, but do not notice the log that is in your own eye? Or how can you say to your brother, ‘Let me take the speck out of your eye,’ when there is the log in your own eye? You hypocrite, first take the log out of your own eye, and then you will see clearly to take the speck out of your brother’s eye.
There obviously is a place for challenging sin in ourselves and others. But let's be known more for confessing our own sin than confessing the sins of others.