Job's friends looked on him with great judgment, trying to convince Job of ways that he had sinned and must repent. Job responded, "But ye should say, Why persecute we him, seeing the root of the matter is found in me?" (Job 19:28)
There are two truths shown by that one question:
1) We are to remember that when we judge, the very same sin is most likely in our lives (perhaps manifested in different ways).
"Therefore thou art inexcusable, O man, whosoever thou art that judgest; for wherein thou judgest another, thou condemnest thyself; for thou that judgest does the same things." Romans 2:1
2) The problem is not "them" but "me." My heart and attitude is not right with God, so thus I am finding gross fault with them.
"And why beholdest thou the mote that is in thy brother's eye, but considerest not the beam that is in thine own eye? Or how wilt thou say to thy brother, Let me pull out the mote out of thine eye; and, behold, a beam is in thine own eye? Thou hypocrite, first cast out the beam out of thine own eye; and then shalt thou see clearly to cast out the mote out of thy brother's eye." Matthew 7:3-5
Are we struggling with judging someone? Perhaps the "root of the matter" is in our own hearts (no matter how much "in the wrong" the other seems) and we must allow God to do a heart-check in us to ensure that we are in right standing before Him.