Romans 11:33
O the depth of the riches of the wisdom of the knowledge of God! His judgments are unsearchable, and his ways past tracing out.
Matthew 11:27
All things were delivered unto me by my Father: and no one perfectly knows the Son, except the Father; neither does any one perfectly know the Father, except the Son; and he to whom the Son may wish to reveal Him.
1 Corinthians 2:10
But God has revealed them to us through the Spirit. For the Spirit searches all things, even the deep things of God.
1 Corinthians 2:16
For who knows the mind of the Lord, who shall give him counsel? But we have the mind of Christ.