Yep, not much profit over long time horizons in correcting a relatively small number of people who are either delusional enough to believe in second comings or think it's a fun bet

To add to that, even if there's zero probability of an actual Second Coming, there's nonzero risk whatever oracle a betting market uses gets hijacked by Second Coming believers who resolve some new Jesus.AI or declaration by a cult leader as representing the authentic return of the Biblical Jesus, plus risks of exchanges defaulting on all bets or your winnings being locked up for gambling-restriction related reasons. For related reasons, you could earn money betting on Trump winning the most votes in 2020 after they'd been counted.