Often times, I find myself being quite judgmental on people I believe have a personal relationship with God but who may still be acting ungodly. We all have had those moments of self-righteousness.
Danny Silk in his book culture of honor-sustaining a supernatural environment writes;
A friend and I were out walking around the property of Mountain Chapel one day. As we were walking, I stepped on a board and a nail went through my foot. I lifted my foot and saw that there was a board attached to the bottom of my shoe. I could clearly see that a nail had entered my foot. But never once did I think, “I’m a nail!” I was, however, very interested in getting that nail out of my foot. And when a child of light discovers darkness in him or her, it does force the issue: “What are you going to do? What are you going to do?”
A Christian does not become a thief because they have stolen, a liar when they tell lies, etc. that person remain the righteousness of God through faith in Jesus Christ (romans 3:21-24).
Therefore, when we encounter someone who has sinned (and may be still sinning), do we identify them by their sin or as who they are in Christ?
I believe remembering that the sin is foreign and not ones identity enables us to deal graciously not only with each other and but also ourselves. This will usually result in resolving the problem and also cause actual repentance.