People tend to get real defensive when they feel criticized. And usually their first words will be, "Don't judge."
But I must tell you, we are to rebuke each other. Not in any malicious way, or the sin is within us, but with love and gentleness. Our motive should be, when rebuking, is to restore that person to the straight and narrow path.
If I become defensive, and rebellious toward someone's correction of my behavior, then my heart becomes hard and harder until a God will just allow me to go, unless and until I become repentant and turn back to him.
“For what have I to do with judging outsiders? Do you not judge those who are within the church? But those who are outside, God judges.
1 Corinthians 5:12-13 NASB
“Do you not know that we will judge angels? How much more matters of this life?”
1 Corinthians 6:3 NASB