In the end it does not matter whether your judgment is right or wrong. Either way you are placing your belief in the unreal. This cannot be avoided in any type of judgment, because it implies the belief that reality is yours to select from.
You have no idea of the tremendous release and deep peace that comes from meeting yourself and your brothers totally without judgment. When you recognize what you are and what your brothers are, you will realize that judging them in any way is without meaning. In fact, their meaning is lost to you precisely because you are judging them. All uncertainty comes from the belief that you are under the coercion of judgment. You do not need judgment to organize your life, and you certainly do not need it to organize yourself. In the presence of knowledge all judgment is automatically suspended, and this is the process that enables recognition to replace perception.
I had a good, long meditation after reading that, let me tell you. I discovered a belief that enlightenment means to judge correctly all the time, which is impossible. There is no such thing as judging correctly, it cannot be real because judgment comes from perception which has no basis in reality. Perception is a position that cannot stand against truth any more than an opinion could lean against a tree. To judge someone is to defend the ego in the form of an attack, utterly fear-based.
A little more from the book:
God offers only mercy. Your words should reflect only mercy, because that is what you have received and that is what you should give. Justice is a temporary expedient, or an attempt to teach you the meaning of mercy. It is judgmental only because you are capable of injustice.
The distinction between "knowing" (knowledge) and "knowing of" (perception) is an important one. Only what is based in reality can be known, therefor perception is incapable of knowing truth because it is based on a positionality. That's not to say you cannot perceive correctly from time to time, but you have no way of "knowing" for sure by the very nature of perception.
At first it may seem frighting to think that you cannot fully grasp truth without..well.. thinking about it. Instead I find it liberating, a real load off my shoulders. By accepting that judgment has nothing to do with knowledge, I can safely focus on letting it go more and more each day. I can work to be more humble, knowing that my perceptions are no more or less real than anyone else's.
My new mantra when I am in a position to judge will be "I don't need to have an opinion on that." I expect they'll still come up from time to time as I live in a world full of opinions, but I'll do my best not to get too attached to them.