Since time-travel for a "time heist" plays a big part in Avengers: Endgame, much discussion has centered on the rules of time travel in the Marvel Universe. Unlike other science fiction, Marvel plays by a very specific set of rules for time travel, making some of the most recognizable setups found in time travel movies impossible. In the Marvel Universe, you cannot travel back and actually affect your past. So, something like Back to the Future could never happen in the MCU, because by definition, the past of the main timeline is fixed.
Marvel operates on a divergence and alternate reality principle. The Marvel Universe is part of a multiverse (a system of related universes) which diverge from one another at critical junctures. These junctures are usually critical points in history or more interestingly, important decision points. The act of time travel always produces a critical juncture diverging a new alternate timeline or world at the moment one enters the reality of another time period, past or future of the time period set out from. Because of this all time travel actually involves dimensional travel. Put another way, in the Marvel Universe, you can never actually travel to your past. You've just traveled to the past of "Universe B."
With this in mind, efforts to change the past result in a divergence that yields two timelines, one where events proceeded as they "originally" occurred, and one where the change occurred and the future was guided by these changes. So, using a popular ethics question, in the Marvel Universe, even if you could travel back in time and kill Hitler as a baby, you have not changed the past and stopped World War II. All you have done is create a new universe where Hitler did not survive infancy. The original timeline where Hitler still rose to power, started the second World War, and was ultimately defeated would still exist and be the controlling history when you returned to "your time."
So if you were drawing a picture of the Marvel Universe timeline, you end up with a straight "main" timeline, with lots of divergent branches. Something like this:
And it got me thinking about what it means to be truly outside of time. We say and believe that God, the Creator of all is outside of time. He is omniscient, He is omnipresent, He is omnipotent. So what does that look like?
I'm not one who believes in pre-destination, in the sense that our actions are programmed, our choices are determined from birth. Were that to be true, that would create a lot of troubling implications. Was Adam free from this determinism, or was his choice to fall already decided? If he was free and his choice was free will, when did free will end? Was it part of the fall? Sometime later? If someone's choices have already determined are they really their fault? And so on.
This is why I struggle with Calvinism.
But again, we are talking about a creator outside of time. Does God's omniscience mean that He sees every implication of every decision that we could make, but that He also ultimately knows the one path that we will take? And He knows the one that He would have chosen for us?
"...For I know the plans I have for you," declares the Lord, "plans to prosper you and not to harm you, plans to give you hope and a future."
That's probably too much for anyone to bear.
And it's why I'm glad we have a God that existed before time, that created time, that set everything into motion, that has set the time for all things to end, and is working to redeem time. That this God interceded on our behalf and stepped into time, to exist with us, along side us, to redeem us.
So that in whatever timeline we're in, we can be reconciled to him.
No Delorean, time stone, or phonebooth needed.