I employ a basic philosophy - before you judge someone, make sure that you know enough facts, and I'm not talking about the surface details (the stuff they let everyone see); I'm talking deep details, real information about that person so that you can make a reasonable and informed decision. In most cases, you don't know their whole story: where they've come from, where they've been, what their problems are, or what worries they face. It is very important to hold off on making any sorts of judgements until you know all the facts related to them. Instead of judging a person, you should try to help them, and if that doesn't seem like a reasonable option, then leave them alone. Not knowing an individual is the most obvious reason why we shouldn’t judge other people.
When you judge other people, you don’t define them, you are actually defining yourself.