Back in my college days this passage and I got off on the wrong foot together. In the Christian campus groups I was involved with, whenever someone started doing something questionable, he or she would immediately go around saying, "Don't judge me!" as a way of pre-empting any confrontation about their behavior. So I took Matthew 7:1 to be a convenient slap-down text used by people who wanted to get away with whatever they wished. As a corrective to this abuse I was later told by some Christian leaders that it is actually okay to judge other people. It's not really judging, they said, it's "spiritual discernment" and you do it for the good of others. Of course no one ever explained to me what the bad kind of judgment is that Jesus forbids. And I also noticed that this so-called "spiritual discernment" we practiced sure did seem to hurt, alienate and exclude a lot of people from our group.
Some years later I've been able to make my peace with this passage even though I'm aware of the ways it is sometimes abused. While it's unfortunate that some Christians do use it in an accusatory manner against others ("Don't judge me!"), the important thing to realize is that Jesus never says, "Don't let others judge you," but rather, "Don't judge others." Sure, people might judge you. That's not what Jesus is focusing on. What's important is that you don't do the same to other people. He's talking about examining your own heart.
"Do not judge lest you be judged." The reason you shouldn't judge is that you wouldn't want to be judged yourself. Jesus' rationale here has a similar ring to his instruction to "do unto others as you would have them do unto you." How should you treat others? Ask yourself how you would want to be treated. Similar guidelines should be used for knowing whether you are judging someone else. Would you want to be judged the way you are judging that person? How would you rather be treated? How would you rather be spoken to if the situation was reversed?
"For in the way you judge, you will be judged; and by your standard of measure, it will be measured to you." Jesus now pushes this thought beyond the theoretical and seems to promise that you will be judged as you judge others. Your standard of treatment will boomerang back to you and you'll get the full taste of either mercy or judgment, depending on what you dole out. I'm of two minds about this. He could be talking about the Day of Judgment. If you lived a life devoid of any grace or mercy in your heart, it will be proof that you never knew Jesus, in which case he will say, "Depart from me" and you will have to face judgment just as you lived a life of judging others.
But he could also be talking about a principle that holds true in this life. If you are a judgmental person, other people will respond to you in kind. In this way God will make sure you get a taste of your own medicine. The reason I lean toward this understanding of Jesus' teaching is that I see it in my own life. Many times I've been on the receiving end of the kind of judgment I used to exercise on other people. Ohhh, I get it. So that's what it's like to be on the receiving end of me. It's a sure-fire method God has used to cure me of some of my blindness. By your standard of measure, it will be measured to you.
I wouldn't go as far as saying you should never confront other people about their sin. In our next passage we'll see that Jesus actually encourages us to do so. But when you have been on the receiving end of being judged, you do learn how to restrain yourself when you are tempted to pass judgment on others. Maybe that person didn't respond to my greeting because she is preoccupied with some bad news. Maybe that person who cut me off on the road is going through a divorce. Maybe I should talk to that person before I claim to understand their motives. Maybe I shouldn't assume I understand where that person is coming from, even though I think I do because of all the gossip I've heard. Maybe that person's silence isn't a guilty silence but a fear of being misunderstood. We're so good at imagining evil when speculating about people's motives. Yet somehow we're not so good at employing our imaginations to come up with reasonable explanations when it comes to giving others a break.