It is listed as the best known verse in the Bible, especially among unbelievers. It used to be John 3:16, but now it's Matthew 7:1. "Judge not, that you be not judged." And the world shouts "Hallelujah!" because now those darned Christians have to shut up or violate their own Savior's commands. Jesus commanded His followers not to judge.
Or did He?
The first hint that this is not an actual command for Christians not to judge in any way is in the context of the command. Jesus warned them to examine themselves -- the famous "log in your eye" section -- and then said, "You hypocrite, first take the log out of your own eye, and then you will see clearly to take the speck out of your brother's eye." (Matt 7:5) Note, then, that Jesus does not rule out "taking the speck out of your brother's eye." He simply requires that they check themselves first. He goes on to say the famous "pearls before swine" comment which, by definition, requires recognition of "swine", a judgment. Just a few verses later Jesus speaks of the false prophets about whom He says, "You will recognize them by their fruits." (Matt 7:16) Jesus meant something, of course, but His "Judge not" simply cannot be understood to mean "Never make a judgment call; you are not allowed to recognize sin or call it sin." He says, for instance, "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." (Matt 18:15) Try to fit that into the standard sense that the world uses when they throw "Judge not!" at us.
What, then, did Jesus mean when He very clearly said "Judge not, that you be not judged"?
Well, first and most clearly, Jesus explained about His own command that our first priority -- our first task -- is to judge ourselves. "For with the judgment you pronounce you will be judged, and with the measure you use it will be measured to you." (Matt 7:2) Whatever measure you're using to judge another, then, be sure you use it first on yourself. That's when Jesus uses that "log in your own eye" metaphor. "You think you're judging rightly, but you're actually overlooking your own large failures while focusing on another's smaller failure." We need, then, to hold ourselves to the standards we're applying to others.
Also implied in the text is a standard. The standard is outside of "me". That is, we don't get to be the standard. We know this because we're supposed to hold ourselves up against this standard. We -- human beings -- don't get to set the standard and say, "All of you need to measure up to me." There is something else, something higher. That is, at issue is not whether we are allowed to recognize sin as sin, but what is the standard of sin. It is not us. It is God Himself and His standard offered in His Word.
One other thing I think needs to be noted. In Jesus's metaphor of log and splinter, you should notice one thing. The aim of this "check yourself out first" thing and judging by the right standard is quite clear. Jesus assumes that the point is to "take the speck out of your brother's eye." (Matt 7:4-5) Identifying sin is not the point. Identifying evil is not the aim. We aren't supposed to simply tell people that what they're doing is wrong. The aim is repair. The goal is to fix problems rather than simply identify them. And when it comes to sin, we are in possession of the best possible remedy. So our pointing out that homosexual behavior is a sin, for example, is a truth statement, but does no good if it ends there. The goal is to remove the problem and that is accomplished by Christ alone.
Despite what you may have been told, Jesus actually told us to be "fruit inspectors" (Matt 7:16). Scriptures are full of judgments we need to make -- recognizing what God calls sin and repenting from it. We must necessarily examine ourselves for it and we are, on the basis of love, commanded to help others in the same thing (e.g., Gal 6:1). Clearly we must examine ourselves first. Clearly we need to address our own errors before we attempt to assist others. Then we must attempt to assist, not condemn, others. That is our "judge not". "Don't condemn them; help them."