The only sign of humility is the love of one’s enemies. When one loves his enemies, he says in effect that they are as worthy of life as he is, that the Kingdom of God does not depend upon the vindication of one’s own cause. When one loves his enemies, he has accepted the fact that he is not the center of the universe. He is willing to admit that the grace of God may be at work, even in his own behalf, in the resistance and rejection he encounters from others. By love of enemies and by this standard alone can the humility of Jesus be measured. The ‘humble of heart’ whom Jesus admires are those whose hearts have no hatred for their opponents.
to Be Faithful
On a personal note, I'm note sure that the only sign of humility is to love one's enemies. Still I can concede the statement given the point Padovano's making.