God's work begins when ours comes to its end.
Sometimes His presence is not felt with power through our methods however useful they may be, especially when we are confident we have the right approach and insights. God has a way of wanting to be God and refusing to get too involved where we have our own wisdom and strength. Then when we run out of wisdom and strength, He is suddenly present, a lesson I find myself relearning practically every day that I am in my right mind. (On my crazy days I am not ready to learn much!)
I think He wants our confidence to be exclusively in Him, and when we lose our self-confidence then He moves in to show what He can do. Perhaps self-dependence--and forgetting the strength to be found in Christ-dependence--is always our biggest blind spot. There is also presumption and pride that go with self-reliance.
So let's not lose our trust in God and the power of His gospel and the spirit of praise which goes with its proclamation (Rom 15:13; 1 Cor 1:18, 22-25; Gal 6:14).
(The Heart of a Servant Leader: Letters from Jack Miller (P&R, 2004), 200-201)