1 Corinthians 2:9-11, 16

That is what the Scriptures mean when they say, “No eye has seen, no ear has heard, and no mind has imagined what God has prepared for those who love him.” But it was to us that God revealed these things by his Spirit. For his Spirit searches out everything and shows us God’s deep secrets. No one can know a person’s thoughts except that person’s own spirit, and no one can know God’s thoughts except God’s own Spirit.

For, “Who can know the LORD’s thoughts? Who knows enough to teach him?” But we understand these things, for we have the mind of Christ.