Cults are like that. One offered Kool Aid. Another locked up children in rooms to be incinerated.
Paul was quoting IKings 19:10-18 Elijah, remember Elijah, that one in which John the Baptist came in the spirit of?
Paul said in ICorinthians 10:11 Now all these things happened unto them for ensamples: and they are written for our admonition, upon whom the ends of the world (flesh age) are come.
Christ repeatedly forewarned that all but the very elect would be deceived. Why? Well look what God told Gideon, Judges 7:2 And the LORD said unto Gideon, “The People that are with thee are too many for ME to give the Midianites into their hands, lest Israel vaunt themselves against ME, saying, ‘Mine own hand hath save me.’.
Oh, who was it that Christ warned would be leading this tribulation of deception? Why it was those coming in His name.