Evil Angels

Q: “Can the evil angels know the thoughts of people?”
A: Angels, whether the good ones or the bad ones, do not possess omniscience. Only God possesses the attribute of knowing all things in His created universe and in heaven. But Scripture informs us that angels do indeed possess great power. Although this power is limited, it is a power which is greater than that of human beings.
In Psalm 103:20, the original Hebrew speaks of the angels as ones who are “excelling in strength.” Jesus used an illustration where he referred to Satan as “the strong man” (Matthew 12:29). And in 2 Peter 2:11, a comparison is made between angels and arrogant false teachers: “…yet even angels, although they are stronger and more powerful, do not bring accusations against such beings in the presence of the Lord.”
When the evil angels fell (some time after the seven days of creation and before the fall of Adam and Eve), it is obvious that this affected not only their former holy standing before God but also their natural knowledge abilities as angels, to some extent. Their natural knowledge concerning anything in God’s creation has been blurred by their intense hatred of God. Two examples easily suffice in showing this. When the devil tempted Jesus in the wilderness, he clearly revealed himself to have less than perfect knowledge of Jesus and His thoughts (Matthew 4:1-11). Just think, Satan actually thought Jesus would bow down and worship him (Satan), yet Jesus Himself was and is the very eternal Son of God! Again, consider how the devil worked hard to bring about Jesus’ death, but he did not grasp the great significance of the crucifixion. The apostle Paul alludes to this when he writes, “No, we speak of God’s secret wisdom, a wisdom that has been hidden and that God destined for our glory before time began. None of the rulers of this age understood it, for if they had, they would not have crucified the Lord of glory” (1 Corinthians 1:7, 8).
Since the “knowing ability” of angels (even in the fallen state) surpasses the knowledge of human beings in many ways, one cannot rule out the fact that evil angels may well know a number of thoughts that people have. Most noticeably this occurs in cases of demonic bodily possession. Apart from these obvious cases, we still have the warning: “Our struggle is not against flesh and blood, but against the rulers, against the authorities, against the powers of this dark world and against the spiritual forces of evil in the heavenly realms” (Ephesians 6:12). We can, however, say with certainty there is at least one thought Christians have constantly which the devil and his minions are not able to fathom: “to know how wide and long and deep is the love of Christ” (Ephesians 3:18). This is why Christians need not worry about what the devil knows, but focus instead on the all-powerful weapon the Savior has given to assure the victory in times of temptation: “The sword of the Spirit, which is the word of God” (Ephesians 6:17).