Trust God with what God already knows.

From Phillip Yancey's book on Prayer:

I know what happens in human relationships when I remain at a shallow level. With casual friends I discuss the weather, sports, upcoming concerts and movies, all the while steering clear of what matters more: a suppressed hurt, hidden jealousy, resentment of their children's rude behavior, concern for their spiritual welfare. As a result, the relationship goes nowhere. On the other hand, relationships deepen as I trust my friends with secrets.

Likewise, unless I level with God - about bitterness over an unanswered prayer, grief over loss, guilt over an unforgiving spirit, a baffling sense of God's absence - that relationship, too, will go nowhere. I may continue going to church, singing hymns and praise choruses, even addressing God politely in formal prayers, but I will never break through the intimacy barrier.

"We must lay before Him what is in us, not what ought to be in us.", wrote C.S. Lewis.

To put it another way, we must trust God with what God already knows.