The silliness begins with the assumption that God and a multiverse is an exclusive “or”. It smacks of denying God because platypuses exist, and they are just too weird to have been created except randomly. Bad logic.
Let’s define terms. Say you take a coin from your pocket, and for no particular reason, you flip it. It is a “heads”, but it could just as likely have been a “tails”. In addition to what it was, the possible other outcome was created, an energetic possibility, a “microverse” in which “tails” was the outcome. But then you put the coin back in your pocket, and the two possibilities collapse back together.
So the term possibility, in this case, means a temporary division of reality.
Later that day, however, you decide to select your career from two choices: either the US Marine Corps, or to become a ballet dancer. Again, whichever one you choose, the other one is also chosen, but the divergence is so great, it transcends a “possibility” and becomes a true “alternative” reality. You essentially create an identical twin in a parallel reality, so you can experience both alternatives. And the alternate reality doesn’t collapse back together with this reality until you are both dead.
Possibilities and alternatives lend themselves to the “bubble membrane” theory of reality, in which events are contained in reality bubbles, that behave a little bit like bubbles in soda. Each bubble defines its own “microverse”, which contains event variables, but is in turn defined by the larger bubbles it is inside. Physical objects continually pass between bubbles with no loss of continuity, as they, along with events, actually make the bubbles in the first place.
I recall in the finale of 'Quantum Leap", that God was a bartender...
(Or maybe Don Ho?)