“Who are you to judge?” is often the indignant reply to a firm statement of right and wrong. Well, I am a sinner saved by grace, and my sin is no less egregious to God than any other person’s sin. As a fellow law breaker, I have no more right to “judge” others and their sin than a prisoner has the right to judge another prisoner.
The problem here is the misuse of the term “judge” when speaking about right and wrong. God provided, through His Word, a detailed list of right and wrong actions. To say “God says that stealing is wrong” is not judging another person who has stolen but rather quoting the law.