I used to think that as well, but closer looking at the bible I think of it as do not be judmental, what I mean is if you are correcting someone out of love you had better not be guilty of the same thing, there are plenty examples in the bible where this is true, I think the bible makes it clear on telling us how to judge some one, I mean if a boy says he is a girl I think it is or Christian duty not to agree with him on the matter. But it is certainly safe not to judge anyone or is it are duty?, it is for sure one my biggest things I struggle with. Here are examples of judging in the bible
2 Timothy 4:14
Alexander the coppersmith did me great harm; the Lord will repay him according to his deeds.
3 John 1:10 -9
I have written something to the church, but Diotrephes, who likes to put himself first, does not acknowledge our authority.So if I come, I will bring up what he is doing, talking wicked nonsense against us. And not content with that, he refuses to welcome the brothers, and also stops those who want to and puts them out of the church.
Galatians 2
11But when Cephas came to Antioch, I opposed him to his face, because he stood condemned.
12For before certain men came from James, he was eating with the Gentiles; but when they came he drew back and separated himself, fearing the circumcision party.
a 13And the rest of the Jews acted hypocritically along with him, so that even Barnabas was led astray by their hypocrisy.
14But when I saw that their conduct was not in step with the truth of the gospel, I said to Cephas before them all, “If you, though a Jew, live like a Gentile and not like a Jew, how can you force the Gentiles to live like Jews?”
1 Timothy 5
As for those who persist in sin, rebuke them in the presence of all, so that the rest may stand in fear.
21In the presence of God and of Christ Jesus and of the elect angels I charge you to keep these rules without prejudging, doing nothing from partiality.
Matthew 18
If your brother sins against you, go and tell him his fault, between you and him alone. If he listens to you, you have gained your brother.
16But if he does not listen, take one or two others along with you, that every charge may be established by the evidence of two or three witnesses.
17If he refuses to listen to them, tell it to the church. And if he refuses to listen even to the church, let him be to you as a Gentile and a tax collector
So I think its important to show people the error in false teachers that could lead them to hell !! but I agree we must not be judgmental when we do this type of thing, and its a very thin line which I have been guilty of crossing plenty of times, Lord forgive me !!!