“Canst thou by searching find out God?” (Job 11:7). Can a man ascend into that eternal realm where God dwells, God, “[who] is light, and in [whom] is no darkness at all” (1 John 1:5)? The thing is preposterous. God is Spirit. “No man hath seen God at any time” (John 1:18). It is impossible. And yet the modern man says, “I don’t understand this. And because it doesn’t conform to the rules of my scientific outlook, I’m going to reject it.” Oh, what a fool the modern man is! What a baby he is, even in the realm of thought. Fancy bringing his abilities and his methods into a subject that, by definition, excludes it all! If people could understand God, they would be equal to God. God, by definition, is altogether “other.” He is the absolute and the eternal, the everlasting God. That is the subject matter of the gospel.
From Martyn Lloyd-Jones, Setting Our Affections Upon Glory