"Shall mortal man be more just than God? Shall a man be more pure than His Maker?" Job 4:17
Mortal man is quite the complicated subject. Mortal man has been trying to take the place of God since the beginning. We should be incorporating God's invisible, spiritual component in our everyday decisions. We are not God, nor do we possess every attribute that God possesses, like: omniscience, omnipotence, immutability. Finding our true place is understanding what attributes we do have that we are in charge of and knowing our parameters/limitations and understanding what will require the hand of God to be completed.
We are not more just than God, but some discernment of justice is given to us to apportion.
We are not more pure than God, but purity of life/lifestyle is for us to seek and find, apprehend, acknowledge and implement.
Justice is only ours to divvy out according to our laws, but the reference here is about a different kind of justice. We do not know other peoples hearts and therefore we need to be careful when making accusations to or about people with whom we have no personal contact. Our justice is to be limited to known events. When we start making judgement on those whom we don't know or have ever met, we have crossed the bounds of our God given rights. This is God's area of expertise and we must refrain as Christians from making judgements beyond our understanding.
Sometimes we think we have the right to cut somebody down or act like we are better than they are, but again this should not be in our job duties. God knows how pure someone is and what their intent is/was and what to do about it. Let's stick to examining ourselves and following God's lead as to what to do about our own behavior.