1 Corinthians 2:10-12 (New International Version)

¹⁰but God has revealed it to us by his Spirit.
      The Spirit searches all things, even the deep things of God. ¹¹For who among men knows the thoughts of a man except the man's spirit within him? In the same way no one knows the thoughts of God except the Spirit of God. ¹²We have not received the spirit of the world but the Spirit who is from God, that we may understand what God has freely given us.