Sometime after David displayed unprecedented courage in defence of Yahweh’s name and defeated a Philistine giant he confessed that fear can grip him.  He consequently strengthened his resolve about what mere mortals can do. David and others like him in Israel’s struggle were not superhuman conquerors.  This was not a flip flop unless David was a superhuman conqueror.

The warrior’s complaint

3) My foes have trampled upon me all day long, For they are many who fight proudly against me. 3) When I am afraid, I will put my trust in You. 4) In God, whose word I praise, In God I have put my trust; I shall not be afraid. What can mere man do to me?

Psalms 56:2-4

God gives faith that people may live by it according to Habakkuk.  In the Christian context living by faith means getting a share of divine nature or a change in the quality of life or a change in identity.  It means coming to life because of faith. Faith is not only an attitude of involvement – to think to do – and the assurance of victory, which is not always the realization of a victory or the thing hoped for. Consider Abraham’s quest for assurance of God’s oath.