I've been wanting to ask you a question for a long time now. In your work, you make it clear that you don't believe that Satan can read our thoughts. Yet I often feel that he's not only reading mine, but in response to them, he's immediately whispering things into my brain. He also constantly distracts me when I pray, etc. Could you mention any Scripture backing up your thoughts about this? I know you have them, but I haven't been able to locate Scripture that verifies this myself. I certainly don't want to give Satan any more credit than I have to.
Concerning the demon mind-reading issue, here's my opinion. First, we know demons aren't omniscient, since they're just angels, created finite beings. Angels don't know a lot of things, including the time of Christ's return (Mark 13:32). There are things "angels long to look into" but apparently cannot (1 Peter 1:12).
We're told that God alone can know the future (Isaiah 46:9-10). That means demons have limited knowledge and can only speculate about the future. Demons are personal beings who are self-contained and are limited in space and time, not omnipresent and therefore presumably not able to drift in and out of people at will. On the other hand 2 Corinthians 10 and other passages show demons can influence our thinking. But can they read our thoughts? Well, we know Jesus knew people's thoughts (Matthew 9:4; 12:25; Mark 2:8; Luke 6:8; 11:17). God knows people's thoughts (Genesis 6:5, Psalm 139, etc.). But nowhere are we told Satan or demons know people's thoughts.
In Daniel 2:27-28 Daniel said to Nebuchadnnezzar that no one speaking by any power but God could tell the king what he dreamed—that included "enchanters, magicians and astrologers" who could appeal to demonic sources. But apparently these demons could not read the king's mind even to ascertain what he had dreamed, much less interpret it. This is probably the primary Scripture that has direct bearing on the issue.
Of course, demons are in an excellent position to deduce what's on our minds since they can see us from the outside. They know exactly what we're reading and watching on TV. They overhear our conversations, see our physical responses, hear even our "private" words, and are no doubt skilled at reading our expressions. They see us when other people can't, any time they wish.
Now as far as putting thoughts in our minds or exercising powers of persuasion, I don't know how that works—perhaps there is a form of telepathy whereby they send a message, plant an idea, without being able to read exactly what we're thinking. I agree there's demonic activity involved in distracting us during prayer, but I don't think they have to be able to read our minds to do this. If we've had an argument with our spouse, if our child is sick, if we're tired and under deadline, he can observe all that and somehow whisper his distractions. (The world and the flesh also provide their own distractions, even apart from the devil-and the flesh definitely does know what we're thinking.)
By hearing us and seeing what we're taking into our minds, demons have a good idea the best things to pick up on in tempting us. That's a critical reminder for us and our children that what we read and watch and look at and listen to provides either the Holy Spirit and righteous angels, on the one hand, or demons on the other hand, ammo in their efforts to wage war in our minds. If I have an enemy attacking me, it doesn't make much sense to hand him a loaded shotgun.
I do think a clear understanding of exactly what we're thinking is limited to the omniscient God who created us, died for us and indwells us. He is the Judge, the only one who knows all, sees all. I find that comforting. It also let's me breathe a bit of a sigh of relief to know that the enemy of my soul doesn't have unlimited access to my mind. He can bang on the door and yell in the window and shout his accusations, but he can't invade the premises of my mind (which is connected with my brain, part of my body that's God's temple) because the Holy Spirit is in residence.
But of course, we must still be on the alert to wage war that demolishes Satan's arguments, and we must not be unaware of his strategies. We don't want to underestimate the power of demons in our lives, but neither do we want to overestimate it.
One other application of this notion is when we feel we're under demonic attack, as I did recently. When a hopeless sense of dread and foreboding fell on me, I called upon the blood of Christ to cover and protect me. I used to do this silently, but now I speak aloud. God hears me either way, but I want the demons to hear too, and the righteous warriors. Jesus responded aloud to Satan during the temptation. He quoted Scripture so the devil could hear it, perhaps also for the benefit of the holy angels.
When we resist the devil, it may not always be appropriate to speak aloud (or to speak loudly anyway, e.g., at a restaurant or in church or at work), but as a rule I think it has merit. By verbalizing God's Word we give shape and expression to the weapons of spiritual warfare. A.W. Tozer entitled one of his editorials, and it became the title of one of his books, "I Talk Back to the Devil."