What is the scriptural evidence for Satan "taking hold" of Christians' minds or implanting/whispering thoughts? Just looking for some solid theology here.

There is a premise that I have seen repeated over and over in Christian circles and it typically revolves around the paradigm that Satan and demons have the supernatural ability to insert themselves into the mind of a believer, take them captive or at the very least “whisper” to them in a supernatural way new thoughts that seem like ones own.

Example:  “An idle mind is the devil’s workshop.” I assume this goes back to Proverbs 16:27, which states idle hands (physical).  And not the devil taking over or setting up shop in the mind of a believer.

Another example: “Satan has really been putting some bad thoughts in my mind lately.” 

I have been researching this and have yet to find conclusive evidence based on scripture that the demonic realm has an active role in inserting thoughts into believers' brains, or the “whisper” theory.

Note: I do believe that a non believer can be possessed and thus have the mind and will controlled by demonic forces, but I have not found conclusive scriptural evidence that as a believer our minds can be infiltrated by the demonic realm.  I also want to stress that I believe in the “flesh” concept of our fallen will and sinful natures and that I can see that Satan and demons tempted others circumstantially.

2 questions:


What is the scriptural basis for saying that Satan or his demons have the ability to enter our brains and have the ability to “take hold” of our thoughts or to implant new thoughts?
I have also heard of the “Satan's whispers” model, where Satan/demons don’t supernaturally inject themselves into the brain/thought life of a believer but rather “whisper” thoughts into a believer's head. What is the scriptural basis for this?
I love Acts 5 (verse 3):


  Then Peter said, “Ananias, how is it that Satan has so filled your
  heart that you have lied to the Holy Spirit and have kept for yourself
  some of the money you received for the land? ...


Peter clearly implies agency of Satan here, and apparently, Ananias and Sapphira, while not necessarily believers, were held in that esteem by the early church.  I would consider this an incidence of Satan directly prompting actions of believers.

This sounds to me like an instance of implanting new thoughts.  I believe this to be the most Biblical supported concept (no quotes as it's a holistic view).