When should we judge and not judge?
Christians are called to judge, and we are called to be tolerant. This seems contradictory at first, but the Bible does have examples where we have liberty and other examples where we have commands. The question is when we apply those two callings. The basic principle is this: Where Scripture is clear, we must be absolutely uncompromising. If something goes against Scripture, we are to oppose it, with appropriate proportionality. If Scripture is silent, we should embrace Christian liberty and we may not judge our brothers in Christ.
It is impossible to go through every single possible example of where this principle applies. There will be some cases where a Biblical principle can be applied, but there is not an explicit enough command to tell someone what they are to do or not do. The purpose of this post is not to address every permutation of this principle, but to advocate for the basic principle itself.
Do we all have different opinions on what is best in various situations? Of course we do. But we must be careful to separate our own particular opinions and preferences from Scriptural mandates. The best solution in the case of a differing opinion (again, not a Biblical principle) is to adopt the posture of "I do not judge you for how you live your life." This is not an example of "hypocrisy." This is having a sense of proportion and not assuming that we know best, when there is no Biblical standard at stake. Let's be humble in our opinions, and absolutely uncompromising on the glory of God.