He's made a career out of writing books designed to give readers a fright, but Stephen King says that while he believes in the existence of evil, he's not convinced it's an external force out to destroy us.

He aired his thoughts on the matter in a Q&A with Rolling Stone magazine to coincide with the launch his new book, Revival, about a Methodist minister who loses his faith.

The Pet Sematary author said he had "gone back and forth" over the years about whether or not there's an "outside evil" and "a force in the world that really wants to destroy us, from the inside out, individually and collectively". 

He wonders how much of it is from the inside and influenced by genetics and environment.

King went on to tell the magazine he suspects "evil is inside us".

"The older I get, the less I think there's some sort of outside devilish influence; it comes from people. And unless we're able to address that issue, sooner or later, we'll f***ing kill ourselves," he said.  

And he sees the West's response to ISIS sweeping across the Middle East as evidence of this.  

"What's the solution?  The only solution we see with ISIS is to bomb the s*** out of those motherf****** so that they just can't roll over the world," he said.

And while humans have spent the last half century searching for extraterrestrial life he suggests "our technological expertise has far outraced our ability to manage our own emotions".

In terms of his own life, King told the magazine that while he doesn't have much time for organised religion he cannot live without a belief in God.   

The Methodist-raised writer said he was through with organised religion once he got to the end of high school but still chooses to believe in God as an adult "because it makes things better".  

"You have a meditation point, a source of strength," he told Rolling Stone.  

"I choose to believe that God exists, and therefore I can say, 'God, I can't do this by myself.  Help me not to take a drink today.  Help me not to take a drug today.'  And that works fine for me."