Darkness, light and illusion
Everything in this world had dual nature. Darkness and Light are contrary, but Lightlessness is darkness, you can comprehend its duality here. When you travel closely towards light, you can apprehend darkness. When you journey towards darkness, you can apprehend light. The ones who stay in the middle of this, eying only the earth cannot apprehend both.
People who do the deeds of Satan like witchcraft can identify a Man of God. Until he stays there, they cannot succeed in their evil rituals. In the life of people like Sadhu Sundar Singh, many such events had happened, we can learn of those from his biography. Those wizards are not the ones who read the Bible, but they can identify a Man of God (of Light). But the ordinary people standing there could not recognize Sadhu Sundar Singh.
Paul only knew Christ, but he could identify an evil spirit that flattered him. Paul became so annoyed and rebuked the spirit. We can read this event in Acts 16:18. An illiterate man with evil spirit who lived in the graveyard could identify the Son of God from distance. But the Pharisees and Sadducees who knew the Bible by heart (by words), could not identify and accept Christ.
Paul did not study demonology, but he says that we are not unaware of the schemes of Satan in 2 Corin 2:11. It is extremely dangerous to travel towards darkness. However, we can see many witnesses even today in which, people who had practiced witchcraft have surrendered themselves to Christ. Both darkness and light are direct and uncomplicated. Darkness can point out light and vice versa. But this world is an illusion. It hides both and shows only itself, as it only exists. It will bind you up with the Laodicean warmth.