I really don't think it's "new" and for centuries poor mental health was thought to be possession, "modern medicine" said no, and opened a whole catalog of causes, effects, and treatments none of which openly recognized or called for intervention by the Church, despite being adept at it...wonder why the Church became sheepish over the whole rite or it's reality.Agreed.
They use this Satan thing as the catch all phrase as the new boogeyman
I'm too much a Heathen to even hint at proselytizing, only offering smidgens from years of listening to Men much more intelligent than I could ever hope to be.
With Free Will comes Personal Responsibility, matters not a belief in a Higher Power.
For there to be a Moral Law, there must be a Moral Law giver...If one can stand in a House of God and proclaim belief, then why would they refuse to believe the possibility of "The Evil One" spoken of in the very Book Religion is based upon?

C. S. Lewis on the Moral Law - CultureWatch
What C. S. Lewis wrote on the moral law 70 years ago is always worth revisiting: A large part of the apologetic method of C.…

Please do not allow my comments to detract from the subject at hand, last thing I want to do is argue the existence, lack thereof, or personal choice to accept or reject a God.