1 Corinthians 2:10-12

these are the things God has revealed to us by his Spirit. The Spirit searches all things, even the deep things of God. For who knows a person’s thoughts except their own spirit within them? In the same way no one knows the thoughts of God except the Spirit of God. What we have received is not the spirit of the world, but the Spirit who is from God, so that we may understand what God has freely given us.