From experience, we know that it is easier to criticize than to correct; we understand that it is easier to find faults than solutions; and we realize that excessive criticism is usually destructive not productive. Yet the urge to criticize others remains a powerful temptation for most of us. Our task is to break the twin habits of negative thinking and critical speech.
Negativity is highly contagious: we give it to others who, in turn, give it back to us. This cycle can be broken by positive thoughts, heartfelt prayer, and encouraging words. As thoughtful servants of a loving God, we can use the transforming power of Christ's love to break the chains of negativity.
Do not judge, and you will not be judged. Do not condemn, and you will not be condemned. Luke 6:37 (NIV)
It's also important for us Christians to examine ourselves. Even the Psalmist said "Cleanse me from my secret faults."
Today me and a group of my friends spent a good 4 hours venting with each other. A lot of it was what the other person does that is wrong, but in a productive way. And for me not only did it help me look at something that I do wrong, but also helped save a friendship that I though I losted.