In my experience, most of the discord, strife, discouragement, emotional pain and suffering in the lives of Christians is caused by judgment. I'm not talking about discernment, but the practice we make of looking at others and thinking ourselves capable knowing what they're all about. We could be condemning them, correcting them, advising them or advising others about them. In every case, we're focusing on the wrong problems. I was a pastor at a church that felt it wasn't good to air grievances directly, so you could go to their "board of spiritual concerns" to whine about anything that bothered you at the church. It really doesn't matter what the issue is, if your eye is on what someone else did wrong, you're looking at the wrong problems...the ones you can do nothing about. The devil would love to keep us there...telling each other what's wrong with them...being hurt when someone tells us about us...never facing the problems we can work on.
There are good reasons Jesus told us not to judge others...instead, He told us to work on our own issues. When we concentrate on improving our own weaknesses and failures, we tend to humbly look on others with compassion and forgiveness. If you're like me, your faults are so many, you don't have time to find fault in others. Another good reason to look at our own faults is because those are the ones we can actually do something about. We have precious little power over ourselves, but we have none over anyone else. If anyone is going to be improved by my efforts, it has to be me. Through the mind of Christ, we have the ability to see our weaknesses and sin. Through the grace of Christ, we can make progress against this sinful nature.
It's this sinful nature that makes us blind to our own faults and expert in the faults of others. Finding fault with others is a way for us to rationalize our own sin. Once you know this, it puts a whole new light on the phrase "constructive criticism." Now, when you find yourself noticing the sins and weaknesses in others, recognize it as a sign from God that you have another load of your own stuff you need to launder.