Luke 6:41-42 "And why worry about a speck in your friend's eye when you have a log in your own? How can you think of saying, 'Friend, let me help you get rid of that speck in your eye,' when you can't see past the log in your own eye? Hypocrite! First get rid of the log from your own eye, then perhaps you will see well enough to deal with the speck in your friend's eye."
We can be our own worst enemies. The Lord clearly tells us how to live. We are to treat one another with a godly love. We are to strive to live peacefully with each other, helping each other to become more like Christ so that together we may bring Christ to the world. We are to practice what we call agape love (see I Corinthians 13:4-8a) amongst one another so that our witness for Christ will not be tarnished. We, however, so often don't act like we should.
We are easily prone to judge others for what we perceive to be true about them and we criticize them, whether it's justified or not. We in essence play God with them. We think we can determine what is in their heart.
Jesus forewarns us about what we need to do before we jump in as judges over others. We must first examine our own hearts and present ourselves honestly to God. We must not attempt to judge the motives of others with anything less than a pure heart before God. We must understand our own sinfulness and repent of it. We are in no position at all to judge someone else when we harbor sin in our hearts.
All of us are sinners and deserve to be judged for our sins. Yet, God is merciful and doesn't do that to us. Everyone should be treated in the same way we want to be treated by both God and man.
Granted, there are times in which sin must be confronted and dealt with, but it should never be done with anything but love and mercy. The goal is always reconciliation and not alienation. Bathe all your attitudes and actions towards others first in prayer---for yourself and for others. Be sure your heart is pure before God before you sit in judgment over others.