Don't judge, so that you won't be judged. You'll receive the same judgment you give. Whatever you deal out will be dealt to you. Why do you see the splinter that's in your brother's or sister's eye, but don't notice the log in your own eye? - Matthew 7:1-3 CEB
The key quote that I think relates to Jesus' idea of "Don't judge" is this one:
If we are going to continue to use language that suggests we get our moral authority from a supernatural source, any group that says that can trump any humanistic endeavour.