Anyway something more interesting you said was the belief that all life came from a single cell. It’s unclear if all life ever to exist on earth had cells or if they evolved later. Also, we can’t tell if life showed up independently fairly frequently but was out competed or just once.
This is somewhat dependent on how life is defined. Prions replicate, but aren’t generally considered alive, yet being fairly simple they should have shown up quite frequently due to random chance. The more complex self replicating matter must be to be considered alive the higher the hurdle for life to have formed randomly but the more likely for simpler self replicating matter to evolve into life. Yet, saying evolution of non living mater results in life seems to twist the meaning around unpleasantly.
PS: Perhaps we should have a new definition between dead matter and living matter which is self catalyzing in the right environment. With viruses or prions siting at the complex side and crystals at the simple end.
Not in a cell, but in porous rock around the hydrothermal vents (at the bottom of the ocean).
Given the exponentialish 'population' growth of chemical soup, coupled with the fact that the very low likelyhood of a localised self-replicator forming, by the time second place came about the game would already be over.
Far more likely is preserved 'mutations' to chemical replicators leading to divergent forms of demi-life.
That’s presumably true, but it means there could have been a very large number of losers not just 1. Aka if extremely primitive life showed up once on earth then it might be a rare event, if it happened 100 trillion times then most planets with the right conditions will have some form of life.
If the spread is too wide then the chance of spatiotemporally cohabiting civilizations of distinct origins will be diminishingly small.
But I don't actually think that the planetary parameters that allow for replication are (in any way) specific to earth.
Consider it in terms of reactions per second - take the likelyhood of non-formation of replicators (call it 99.999999999% - because it actually does not matter), to the power of the number of reactors, to the power of the number of seconds since the universe began.
The likelyhood that no self-replicators form rapidly plummets to a vanishing value.
Also, the fact that you think a being of unfathomable complexity can just be, but everything else needs a source is rather silly.
(The other possibility being infinite regression, which is equally silly.)
Now that said, if we did find alien life, how would your feelings about God change?
There’s no mention of a ton of very significant things we now know to be real in any holy book. Why isn’t that stuff enough “proof” they’re “fake”?
I also reject your out-of-hand assertion that whatever one thinks about the world's existence has the same meaning to someone as your mythical being has to you.
How blown would your mind be if I posited to you that what you call "GOD" is the universe? Your holly book says he is everywhere and everything all at once, does it not? That "He is within all of us", and yet we are the universe observing itself. He came about out of nowhere with no trace of origin? We don't know what caused the big bang, it just happened.
If aliens exist, it's because the universe "allowed" it to happen (aka the statistical probability is high enough for it to occur or we would not be alive having this conversation) not some conscious divine being.
Still labeling pre Big Bang as SpaceTimeTime or calling that Space Time and relabeling what we experience as local space time doesn’t really matter here. The point is our Big Bang could be happening infinite times in a multiverse without beginning or end. That’s one possibility where there isn’t anything conscious to point to as a GOD just the same kind of things which make up physical reality.