I think the scariest thing about a world government isn’t some daft prophecy about the antichrist but that if it turned tyrannical there’d be very little anyone could do about it. Power inevitably corrupts and to say otherwise is wishful thinking; we’d have created the ultimate power and therefore the ultimate source of corruption, imagine the world government underwent a palace coup and we ended up with a regime like Stalin’s or Mussolini’s but you couldn’t even flee it as a refugee or hope for foreign intervention.

Balances of power rather than monopolies on it are probably best in my opinion.