Maybe you tried to tell someone a hard, true thing, and they answered, “Who are you to judge?” and the conversation was over. Matthew 7:1, “Judge not, that ye be not judged,” is usually what stands behind that question. It does not mean never judge anything. Jesus forbids judging others by a standard you would not accept for yourself, and he tells you to deal with your own fault first so that you can “see clearly” to help.
“Judge not” was never meant to keep you quiet when someone is being hurt. Saying that what someone is doing is wrong is a different thing from condemning the person who does it. You can call the action wrong and leave their heart to God.
The paragraph, whole
Judge not, that ye be not judged. For with what judgment ye judge, ye shall be judged: and with what measure ye mete, it shall be measured to you again. And why beholdest thou the mote that is in thy brother’s eye, but considerest not the beam that is in thine own eye? Or how wilt thou say to thy brother, Let me pull out the mote out of thine eye; and, behold, a beam is in thine own eye? Thou hypocrite, first cast out the beam out of thine own eye; and then shalt thou see clearly to cast out the mote out of thy brother’s eye.
Matthew 7:1-5 (KJV)
A mote is a speck of dust. A beam is a piece of lumber. The picture is a plank sticking out of your own eye while you squint at a speck in your brother’s.
Many people remember the first line as “Judge not, lest ye be judged.” The King James has “that ye be not judged,” and the next sentence gives the reason: the measure you use on others is the measure used on you. That is a warning about hypocrisy and harshness, aimed at the critic who has exempted himself. Paul says it in Romans 2:1: “wherein thou judgest another, thou condemnest thyself; for thou that judgest doest the same things.”
Read to the end and the paragraph does something people seldom quote it for. It finishes with you seeing clearly and helping your brother with his speck. Matthew 7:1 gets quoted without the four verses that finish it, the way Philippians 4:13 gets printed without the hunger in the verse before it.
Jesus expects you to tell things apart
The very next verse needs judgment, and it uses a hard picture to say so: “Give not that which is holy unto the dogs, neither cast ye your pearls before swine,” in Matthew 7:6. Whatever else it means, it means you will have to decide what is safe to hand to whom. Further down the same sermon Jesus warns, “Beware of false prophets, which come to you in sheep’s clothing,” and gives the way to recognize them: “Ye shall know them by their fruits,” in Matthew 7:15-16.
On another day, arguing with men angry about a healing he had done on the Sabbath, he put the two kinds of judging side by side:
Judge not according to the appearance, but judge righteous judgment.
John 7:24 (KJV)
Judging by appearance is forbidden. Righteous judgment, which looks past the surface to what is really happening, is commanded.
“Who are you to judge?”
That question is close to James 4:12, “who art thou that judgest another?” and Paul asks a near cousin of it in Romans 14:4: “Who art thou that judgest another man’s servant?” James has a real point. He is writing about believers speaking evil of one another, “Speak not evil one of another, brethren,” in James 4:11, and he reminds them there is “one lawgiver, who is able to save and to destroy.” Paul says the verdict on what is in a person’s heart waits for the Lord: “judge nothing before the time, until the Lord come,” in 1 Corinthians 4:5.
So two things are true at once. The final word on another person, and the reading of their heart, belong to God. Whether an action is wrong, and whether you ought to say so, is a question Scripture expects you to answer, carefully and humbly.
Beam first, then help
When the person you need to talk to is the one at fault, Paul describes how it is supposed to sound:
Brethren, if a man be overtaken in a fault, ye which are spiritual, restore such an one in the spirit of meekness; considering thyself, lest thou also be tempted.
Galatians 6:1 (KJV)
That is the order Matthew 7 gives. Look honestly at your own eye first. Then go, in the spirit of meekness, to restore. When “judge not” is said to you, check your own eye, and if it is clear, go on, gently. By the end of that paragraph Jesus has you standing close enough to work on somebody’s eye, and nobody ever got that close by backing away.