Judging is a complex issue as we have to make thousands of judgements a day, but judging another person, not their actions but the person themselves, is a special case. Judging entire groups (e.g., homosexuals, infidels, gentiles, atheists, women, etc.) also falls in this category. In my opinion this is where "judge not lest ye be judged" clearly applies. So how to deal with people who judge, should we judge them? Well, yes. Judging someone for judging is not the same as judging the person themselves. When someone condemns another human being based on religious beliefs they are sinning (or acting in ignorance from a Buddhist perspective) so opposing them is an act of compassion. We should show them the right way and stand up for the people they are victimizing. If it's their religious or cultural beliefs informing the judgement, then those beliefs are wrong and should be actively opposed. That's the great thing about religion, it's not relative, there is right and wrong. But there is a split amongst religious people, there are those who use rules to judge others, and those who follow compassion to judge others. Both cannot be right. There can be no compromise, no quarter given. Jesus was clear on this, the Buddha was clear on this. Compassion trumps rules, always.