I will prove to you that God exists

[GrandizerII]

Fine, you're a multiverse person. Most atheists aren't willing to concede the multiverse theory is necessary and because there is no direct evidence of other universes. I respect it as a plausible theory and an explanation for fine-tuning of the universe for life. However, it also multiplies entities to infinity and beyond ala Occams razor. I consider it the ultimate time and chance, naturalism in the gaps theory.

There is no direct evidence of God either, so we're even.

Also, people subscribe to a multiverse view for various rational reasons, and not because they need it to explain something like the assumed "fine-tuning" of this local universe. Even some theists have argued for a multiverse view in favour of God because of things like the principle of sufficient reason.

The multiverse is just as much about "chance" as God is. Is God "chance"? Nope? Then good luck arguing the multiverse (without God) is any different in this case.

Also, multiple worlds doesn't mean less simplicity, especially if fundamentally they are all of the same "quality". One could argue the addition of a supernatural being to what is otherwise a natural reality is unnecessary and is therefore what violates Occam's razor.