I used to be judgmental when I was younger. But now, at 36 - life experiences have taught me that I am not above any bad act. It's by the grace of God that I have refrained from certain mistakes and it's by the mercy of God that my shameful mistakes have not significantly altered my progress in life.
Christians must take the stance that no one is beneath us regardless of the outward behavior someone may be displaying. To the woman caught in adultery Jesus said let the one who is without sin cast the first stone. (John 8:7). Jesus understood the hypocrisy (Matthew 7:5) in condemning others when oftentimes we have done the same things or are liable to do similar acts if put in certain circumstances.
This concept of non judgment is very triggering to certain Christians because we may feel that bad behavior is a poor witness to the truth of the gospel. Additionally, we may feel that sin leads to death, and we personally have a duty to our loved ones to call out sin in their lives in order to be iron that sharpens iron in their lives. Proverbs 27:17.
Here's the thing, when we come out against the sin of others, many times we do this in a self-righteous way. We lead with our egos and not love and humility. We try to play the role of the Holy Spirit when truly we are meant to come alongside our sister with their well-being in mind. If we confront sin in others with the wrong attitude devoid of humility, understanding and compassion we have the potential to do more damage and reinforce the sin that's occurring in the life of our sister. So if you must judge, judge rightly with your own shortcomings in view. For in the same way you judge others, you will be judged, and with the measure you use, it will be measured to you. - Matthew 7:2