Let's Take A Look At The "Judge Not" Argument For A Moment!
It's very interesting to me how Christians are quick, these days, to pull out the old "judge not lest you be judged" excuse when they are angry at you for warning people away from their favorite false teachers and false prophets by name. They come down on those who test the spirits (1 Jn. 4:1), discern truth from error (Phil. 1:9-11, Prov. 3:21) and judge rightly (Jn. 7:24) when those are ways in which God has told us we ARE to judge. They use the "judge not" ploy to make themselves look like they are holier-than-thou and above the fray, and in so doing they are already in violation of Matt. 7:1 because they are hypocritically judging those they say are being judgmental. But think about the ways in which we all tend to judge wrongly and unbiblically in a whole variety of ways every day.
Christians are quick to talk about how bad it is to gossip ... then they go right out and do it themselves. They pass around unverified stories, backstab, slander and criticize people based on personal preferences rather than on their teachings, prophecies and fruit of the Spirit. They continually judge others on the basis of:
Next time you want to accuse someone when they are testing the spirits (1 Jn. 4:1), discerning the difference between good and evil (Heb. 5:14, Eph. 4;14), or judging whether or not a person is teaching false teachings (2 Tim. 4:3, Titus 1:9), making false prophecies (Duet. 13:1-5, 18: 20, 22), and not evidencing the fruit of the Spirit in their lives (Gal. 5:18-25) ... maybe you need to apply "judge not lest you be judged" to yourself. Learn to judge in the ways God commands you to judge, and stop judging those who practice biblical judging. The fact is that you are guilty of hypocritical judgment every day of your life. God wants us to judge those inside the Church because He will take care of those outside (1 Cor. 5:12-13). We need to judge teaching and prophecies against the truth of God's written Word, and whether they exhibit the fruit of the Spirit (Matt. 7:15-20). We need to test the spirits. We need to test everything, hold on to the good (1 Thes. 5:21)!
Read this article: How To Discern, Test and Judge Rightly by Sandy Simpson