A quote I do not want to lose: "Man must know God or perish, but, unless he knows him as the ultimate mystery, he does not know him at all." --G.B. Caird, Paul's Letters From Prison (p. 70)
(In the commentary, this appears in reference to Ephesians 3:19, the paradox of knowing the unknowable love of Christ. But it applies much more generally.)
This line feels so true and pointed to me. American Christians are so in danger of losing the mystery. We don't like the loss of control, the surrender of power, the admission that we don't understand everything, the awareness of being limited. We are told all our lives: You can do anything, if you set your mind to it. Shoot for the moon! The worst that can happen is that you'll fall among the stars. Nothing's impossible. Nothing is out of reach.
But the reality is that God is out of reach. A god is something people worship. A true God is a god worthy of worship--an entity higher than which there can be no entity, thus omniscient and eternal, non-contingent, thus beyond our comprehension. If God were completely comprehensible to us, He couldn't be much more than a human, in which case I can't see Him being worthy of worship. So: He is greater. He is inconveniently incomprehensible, mysterious, wild.
We want God in 10 bullet points on 3 powerpoint slides, illustrated with clipart. We want God in a nice package, a little box that fits in a purse. We want God in convenient capsules, to be taken with a glass of water before bedtime.
If we shop for a convenient, condensed, succinct, useful, comfortable God, we won't know God, but only a construct. If we want the truth, the God who transcends our small minds, we must take the risk of acknowledging that we can't grasp everything. We have to humble ourselves by acknowledging that we are not God. Only He is God, and only in recognizing that can we approach Reality.