To judge others is to take law into our hands.
When we see anyone doing something wrong, we immediately begin to think about it and judge them based on whatever we have seen. When we bring any such negative thoughts we will not be able to help in any way to overcome the weakness.
We need to remind ourselves that we have no right to judge others. The only thing we need to do is to see if we can help them out in anyway to overcome their weakness. If not, we need not think or talk about it, i.e., we need not take the law into our hands.