“Judge not, that ye be not judged.” This is attributed to Jesus in St Matthew’s Gospel (7:1). And, boy, is this particular quotation from Scripture over-used. The usual application? Don’t tell anyone that what you consider to be immoral or otherwise bad behavior is wrong. This passage is often used to, in essence, excuse behavior that is otherwise inexcusable.
But to judge, in the common English sense of the word, means to discern, to distinguish, to characterize. It’s not “judgment” in the sense of the Gospels. That sense is clear from this passage from the Gospel of my namesake, St John (5:25-29):
Verily, verily, I say unto you, The hour is coming, and now is, when the dead shall hear the voice of the Son of God: and they that hear shall live. For as the Father hath life in himself; so hath he given to the Son to have life in himself; and hath given him authority to execute judgment also, because he is the Son of man. Marvel not at this: for the hour is coming, in the which all that are in the graves shall hear his voice, and shall come forth; they that have done good, unto the resurrection of life; and they that have done evil, unto the resurrection of damnation.
God will judge us, at the end. While we are here on this Earth, we need our judgment. We need to judge what is right, what is wrong, what is good, what is evil. And, if we’re able, act on those judgements.
Those who don’t judge in this sense, and let pass and do nothing about things that are evil, will likely not be well judged in the end. By God; not by me, or thee.