He's not talking about what he believes, he's a nihilist
Respectfully disagree based on my personal experience being raised in a church that was very focused on revelations. IMO you'd have to grow up believing it yourself to understand.
He's saying what would have to be true to justify what he plans to do.
Yea their logic is circular but I promise you they fucking believe this shit.
Barring specific evidence to the contrary, both Occam & Halon's razers apply here. It is both a simpler explanation that he believes the scriptures in his religion AND there is no malice required for stupidity to explain what he's saying.
I'm not saying JD is above lying to his followers and faking faith. But I am saying that I don't think he's smart enough to do that and he's probably 100% serious.
This revelations talk is conditioning them towards violence.