God does not forbid us from being a judge of character, he just wants us to turn the gavel on our own heart before seeking to turn it on those around us. In doing this a righteous judge will form within us, not based on hate, but based on love. Think of how much injustice has been spread in view of perceived injustice. How many wrongs have I done in response to someone wronging me? Justice can not be free to do its work in others unless it first does its work within me.