|4. But Jesus, perceiving their thoughts, said, "Why are you thinking evil in your hearts? (Matthew 9, see also Luke 9:47)|
The word of God reads and judges our thoughts and attitudes. Everything we think can be clearly seen by him. In the book of Hebrews, the apostle Paul states that God's spirit can find out all of the thoughts and desires in our hearts. Absolutely nothing is hidden from the Great God!
12. For the Word of God is living and powerful, and sharper than any two-edged sword, piercing even to the dividing asunder of both soul and spirit, and of both the joints and the marrow, and is able to discern the thoughts and intents of the heart. 13. And there is not a created thing that is not manifest in His sight; but all things are naked and laid bare before the eyes of Him to Whom we must give account (Hebrews 4:12 - 13, HBFV).
The devil knows HOW humans think because he thinks the same way. He knows the weaknesses of human beings and therefore knows how to tempt us. Jesus referred to this commonality of thinking when he rebuked Peter (who was not yet fully converted) at a moment when the devil was influencing him to think and say certain things. Peter, upon hearing Christ say he must be put to death in Jerusalem by the Jewish religious leaders, began to correct him! Jesus did not hesitate to answer what was being said.
'Get away from me, Satan! You are an obstacle in my way, because these thoughts of yours don’t come from God, but from human nature' (Matthew 16:23)
The devil cannot and does not know our innermost thoughts. He simply cannot read our minds, otherwise, he would not have wasted his energy trying to tempt Job (Job 1:6 - 12), or even Jesus when he was a flesh and blood human (Matthew 4:1 - 11).
The devil certainly does have the power to deceive those who do not follow God.
Jesus, when He died for our sins and began to establish his kingdom, put Satan under the power and authority. The devil no longer has power over us - and through God we can assurred that he cannot read our thoughts.