The gospel opens with a simple command
Stop judging, that you may not be judged.
Taken out of context this verse would seem to promote a complete laissez faire individualism. You live your life I live mine. Who am I to judge?
The word judge here is used in the sense of legal proceeding, the last judgement. Matthew uses the same word in 19:28 when he tells them that the apostles will eventually at the resurrection sit with him in judgement. Judgement requires a decision about action by also about motive.
As Christians we believe there is right and wrong, there is a natural law that God has planted in the human heart and a law that God has revealed. We should constantly be engaged in the process of discernment. And yes we not only have the right but the obligation to discern not only when our own behavior is in accord with that law, but also the behavior of others. To sit in silence while the dignity of another is being abused would be a sin of omission. The basic concept of society requires that we have some common set of norms of right and wrong behavior.
The judgement we cannot render is the judgement that claims to look into the heart of another and know why they are behaving the way they are. Certainly our judicial system must as best it can determine motive, but we know how imperfect that is.
Here Jesus is speaking to us as individual disciples and reminding us that if we wish to be forgiven, we must forgive.
For as you judge, so will you be judged, and the measure with which you measure will be measured out to you.
We all have bad days, we all make mistakes, we all need to apologize. We should be ready to accept the apology of others. And even when they don't apologize cut them a break.
Our language often reveals our attitudes. What does it say about us that we can still say "excuse me" but if someone offers an excuse, that is a bad thing. When did we turn "excuse" into a bad word. The word originally meant simply an explanation of the mitigating circumstance.
Step one it seems to me it to distinguish when someone is doing something truly wrong (against God's law) and when they are just not doing it the way we think it ought to be done. They latter is our problem not theirs.
But even when what they are doing is truly wrong, we should assume the most benign motivation (a mistake) first and only move to a more sinister motivation when there is clear compelling evidence.
And even on those few occasions when we are sure they not only did a wrong thing, but they freely chose to do it, and for a bad motive, we must be ready to forgive.
This kind of discernment isn't quick and often requires not only thought but prayer. The snap judgment is so much easier; that's why we do it.
Today when you find yourself offended, angry, or just annoyed by the behavior of another. Try being Christian, it makes for a much less stressful life.