Intrusive thoughts

I was asked about Christians who suffer from intrusive blasphemous thoughts. There are different possible explanations:

i) A naturalistic possibility is that that their brain is doing funny things, and they need psychotropic medication to stabilize it. That's not a cure, but it can sometimes provide necessary relief. 

I have a relative whose parents thought it was a swell idea to send her to a missionary training school in Canada when she was an adolescent girl. She developed mental illness as a result of the isolation, and remains on medications to this day. 

I have another friend who suffered from night terrors and old-hag syndrome until he was diagnosed with sleep apnea, and underwent some sort of treatment, which greatly diminished the symptoms (as I recall).

ii) There's also the question of whether the individual is under too much stress at work, home, or school. 

iii) As to where such thoughts come from, most American men have consumed lots of unsavory stuff (myself included). Although we may keep that quarantined in the subconscious, it's still there. 

Martyn Lloyd-Jones talks about an elderly man who was very devout, but after he developed dementia, a different side surfaced–the side he self-censured when he was in his right mind.

iv) As for supernatural explanations, if evil spirits have access to human minds, then they might be able to plant blasphemous thoughts in human minds. Demoniacs could discern the true identity of Jesus, which suggests telepathy. Here's another example suggesting that demons can read minds:

http://triablogue.blogspot.com/2017/11/jesus-and-psychiatrists.html

v) As our country becomes more anti-Christian, there's probably a resurgence of paganism, so that may be in the air (so to speak). The experience might be like missionaries who go to countries steeped in witchcraft, and find themselves under psychological attack from unseen forces.

vi) Another possibility is that someone hexed the Christian who now suffers from intrusive blasphemous thoughts. 

vii) Just in general, I think human psychology is different at night, in the dark. We're more vulnerable to fear and doubt. That can have a naturalistic explanation, but it can also be opening for malign supernatural agents.

viii) I wouldn't worry about the unforgivable sin. Intrusive thoughts are involuntary. That's hardly comparable to the Gospel accounts.