God, with capabilities as stipulated by Christianity, had, as far as we can tell, any number of methods available to generate faith. You were the one postulating that the resurrection was necessary, not me. I can easily envision that the key is, say, opening one's mind upon hearing about Jesus, making one ready to receive a direct sense of the existence of God, was how it worked. Then people invented stuff about the resurrection, but it never prevented that more direct feeling of divinity, which was the key, so it wasn't removed.

You have my point about the airliner backwards. Suppose we didn't know anything about how airliners came to be. We just observe people working, and boom! Airliner. But we know it's impossible to for people to create that in one shot, so we invoke God. That is clearly wrong. Not knowing the process doesn't mean it doesn't exist! We can observe incremental improvements and changes from the 787-8 to the 787-9, but they weren't the same as the incremental improvements that went from nothing to 787-8.

We don't know what chemistry is possible, or what the conditions were on the early Earth (not in sufficient detail), so we simply don't know. We have an incredibly potent process for refinement, and we don't know whether or not it could have gotten going. We're trying to figure out some of the basic science (e.g. https://www.nature.com/articles/s41570-023-00524-8) but the only honest assessment at this point is that we don't know what we need to to make any assessment either way.

Regarding justice, love, morality, and so on, if one starts with transcendentally powerful notions of all of those, yes, of course one needs something like God. But if these things are simply reflections of human nature, then no, one doesn't need such things at all. Yes, Hitler got away with it, in some sense--I mean, he died, and his goals were thwarted, but he was responsible for the deaths of millions and there will be no extra accounting for that. It's our job to ensure there won't be more Hitlers. It's on us to get these things right.

Cooperation is extremely powerful. If might makes cruelty, then cruelty prevents cooperation, and the mighty become weak. The superior solution, if one can achieve it, is to cooperate. In some organisms, like ants, this is achieved without regard for the welfare of the individuals; but in more complex organisms like us, only the reasonably-well-treated organisms have the capacities needed, so it's entirely reasonable that there was a fitness advantage to things like kindness and care, to help the weaker become strong and productive so that we can all cooperate and be greater than who we were individually. (Baboons have a lot of trouble with this.)

If you start out with the rationalizations for human behavior and emotions given by Christianity, and then you throw away Christianity but try to keep the rationalizations, it is very confusing. Nietzsche saw that quite clearly, but he wasn't much use in building a more reality-based perspective. Partly it's because he wasn't particularly enamored of a thoughtful scientific approach; but partly he was just born too early and couldn't benefit from the immense expansion in knowledge that happened in the 1900s. There's really no excuse now; it's just cultural habit that we're working through little by little. Anyone who wants to, these days, can have a both enriching and reality-based perspective on human nature. Christianity is much easier, though, to get that from; it's had a couple thousand years to figure itself out.