Faith

Psalms 139:6 KJV
Such knowledge is too wonderful for me; it is high, I cannot attain unto it.

David says he knows something that he cannot know.

He knows truth about God.
He knows God has searched him
He knows God is acquainted with all his ways
He knows he cannot flee from God's presence
He knows God possessed his reins in his mother's womb
Yet though he knows it, he cannot attain unto it. It is above him even though it has been revealed to him.

So it is with faith. Faith knows things to be true.
Faith has researched the evidence
Faith reads the articles from those who have studied these things before him.
Faith listens carefully to the preaching and searches the Scriptures to see if these things be true.
Faith can articulate its position.
But when all things are said and done, faith still cannot attain to and say it has hold of even those truths it has discovered. God is too high, too wonderful for the human mind to ever fully attain to it. We simply rejoice that we get to know the truth, not that we have to fully solve and prove it.