Sometimes God shows up in power and might. Think Elisha and the prophets of Baal. Or Isaiah in the year King Uziah died. Or God talking straight with Job. Think the crossing of the Red Sea. There can be no mistaking the power, majesty, glory, and dominion of God in those moments.
But think, too, of the still small voice. Remember Jesus' silence before Pilate. Call to mind God walking in the Garden in the cool of the day, and asking simply, "Adam, where are you?" This moment in Abraham's life is an encounter with God. And God somehow manages to interact with him in such a way that he does not die (Exodus 33:20).