God opposes the proud but gives grace to the humble

"God has surely promised His grace to the humbled: that is, to those who mourn over and despair of themselves. But a man cannot be thoroughly humbled till he realizes that his salvation is utterly beyond his own powers, counsels, efforts, will and works, and depends absolutely on the will, counsel, pleasure and work of Another -- God alone. As long as a man is persuaded that he can make even the smallest contribution to his salvation, he remains self-confident and does not utterly despair of himself, and so is not humbled before God. Such a man plans out for himself - or at least hopes and longs for - a position, an occasion, a work, which shall bring him final salvation, but which will not. Conversely, the man who is out of doubt that his destiny depends entirely on the will of God, despairs entirely of himself, chooses nothing for himself, but waits for God to work in him; and such a man is very near to grace for his salvation." (Martin Luther, "Bondage of the Will")