A commonality of most cults, in the sense that their particular group alone has validity, under one leader or office to whom they give a implicit loyalty as a type of Christ, versus Mk. 9:39,40
I remember being in a public place and overhearing a millennial enthusiast “witness” to someone. He said, excitedly, “Obama is the AntiChrist!” (he quickly rattled a chapter and verse Hezekiah 3:14 or whatever) then he said with confidence and ecstacy, “New York City is Babylon (another chapter and verse) and it will be destroyed in a nuclear explosion and it will happen this year!” I looked over at him and he seemed like he was beside himself with joy. This was, I think, two years ago.
That is what happens when some people who call themselves Christians get caught up in date setting and idle speculation. They don’t talk much about Christ. Instead they “witness” about some numerology trick they came up with or the latest revelation from their T.V. preacher.