Our pastor brought a thimble to church. I was sitting so far back that I could barely see it. He held it up between his thumb and forefinger and stood in front of the pulpit. “If what there is to be known about God is an ocean,” he said, “this represents how much we know.” His illustration stuck with me, and I thought about it again last week as I walked through a sea of people at Mayo Clinic in Rochester, MN. The Mayo campus there has many buil…