The source of humility is the habit of realizing the presence of God. Humility does not mean thinking less of yourself than of other people, nor does it mean having a low opinion of your own gifts. It means freedom from thinking about yourself one way or the other at all.
Humility means that you feel yourself, as a distinct person, out of count, and give your whole mind and thought to the object towards which they are directed, to God Himself in worship and to the fulfillment of His will in Christian love; and humility, in that sense, is quite plainly a source of effectiveness. The humility which consists in being a great deal occupied about yourself, and saying you are of little worth, is not Christian humility. It is one form of self-occupation and a very poor and futile one at that; but real humility makes for effectiveness because it delivers a man from anxiety, and we all know that in all undertakings, from the smallest to the greatest, the chief source of feebleness is anxiety.
There is nothing big enough to hold a man's soul in detachment from the center of himself through all the occupations of life except the majesty of God and His love; and it is in worship, worship given to God because He is God, that man will most learn the secret of real humility.
~ William Temple, Christ in His Church