I knew Heavy Metal,Acid Rock, was religious in nature back in the 70s when I was in it. We had all kinds of spiritual experiences. All the spirits involved were demonic spirits. But hey; you don't have to get in a time machine and go to 70s acid rock concerts to find them now. Just go to your nearest Fad Driven church, they have imported the stuff in for today, and all under the name of Relevance and Freedom.
They could simplify it greatly by if all these unchristian people register themselves as Satan worshipers, because that is what they are.
Martin Luther wrote: Now, what good does it do you if you know that there is a God, if you do not know how He feels about you, or what He wants of you? People have done a good deal of guessing. The Jew imagines he is doing the will of God if he concentrates on the Law of Moses. The Mohammedan thinks his Koran is the will of God. The monk fancies he is doing the will of God if he performs his vows. But they deceive themselves and become "vain in their imaginations," as Paul says, Rom 1:21 . Instead of worshipping the true God, they worship the vain imaginations of their foolish hearts.