Thoughts are a very private matter. They are in your own head–a place where no human can enter other than you. So how is it that someone can say, “I know what you’re thinking”?
The Bible speaks about this when it says, “For what man knows the things of a man except the 
spirit of the man which is in him?” (1 Cor. 2:11). Paul’s rhetorical question proves the point–no one can know “a person’s thoughts except the spirit of that person” (ESV). He then proceeds to his main point–“Even so the thoughts of God no one knows except the Spirit of God.” The Spirit of God knows the thoughts of God, and Paul said that the apostles had “received…the Spirit who is from God, so that we may know the things freely given to us by God” (2:12). The Spirit of God told the apostles what God thinks, and then Paul said, “These things we also speak…in words…which the Holy Spirit teaches” (2:13). They wrote down God’s thoughts!
How cool is that! When you read your Bible, you are reading the very thoughts of God!