But the general point is this: Many of these creation myths and other religious beliefs are similar to one another, because they share relatively common geographical/cultural origins or were simply pushed onto indigenous peoples of other regions. They're not similar because there is some spiritual force/god(s) flowing through the universe influencing people to write similar things; they're similar because they're influenced by each other.
These kinds of arguments were popular in so-called "history of religions" circles until several decades ago, but they were generally abandoned. Atheistic fundamentalists and some people who took older religious studies classes still haven't caught up entirely. The thesis was basically that Christian theology took its primary components from preceding traditions rather than from events which occurred in Jesus' life. Usually it works this way: Jesus preached an inner kingdom of hippie social justice, but Paul put Jesus in the framework of a "mystery religion" (a category of pagan cult contemporary with early xianity). It turns out that you have to read those pagan cults using the terms of Christian theology in order to make that case, but obviously if you're using the terms of Christian theology to read pagan cults then the thesis that the terms of Christian theology are basically lifted out of the mystery religions is false.
The stories are similar because they are products of each other, not because there is some supernatural force guiding a common story throughout each of them.
Consider the first paragraph on this website here
, which I think parallels your point:
"What the ancient evidence will show you is that ancient western culture had a conceptual model of reality, and ancient Christianity adopted that model. Ancient Pagans believed in various levels of divinity, with miraculous powers, coming down and going up to its home in the sky. Divine beings cared about people, listened to and answered their prayers. Gave them the power to prophesy. Even gave them a better deal in the eternal life that comes after death."
So the facts are:
1. They believed in some sort of non-human beings.
2. They beleived that non-human beings had non-human powers.
3. They believed that non-human beings lived in places that humans don't.
4. They believed that non-human beings interacted with humans.
5. They believed that non-human beings could provide humans with non-human knowledge and power.
Obviously these are so vague that we would only be surprised if there weren't people all over the world who believed these kinds of things. This is basically on the order of, "Many people believed things fell from the sky in ancient times, so Newton must have gotten his laws of motion from them." (There exist much better examples than this website, but...)
Leithart offers the interesting epigram, "The Devil has no stories." In other words, because only God can create out of nothing, whenever we make anything it will always be derivative in nature, so any story we write will unavoidably reflect the story, God's story. Hence we get posts like some of those above.
So, are there similarities? Sure, but not any kind of similarities that show that the fundamentals of Christian theology were derived from the mystery religions as opposed to the life of Jesus.
It's not exactly an accident that the Hebrew creation story shares great similarities with the Egyptian creation story. It's not exactly an accident that the story of Noah shares great similarities with numerous other stories of global floods. It's not exactly an accident that the identity of Jesus Christ shares great similarities with the identity of Mithra...it's really not that unreasonable to conclude the Egyptian creation myth was an influence.
It is true that they all have some pretty exact details (of many of these early myths) that were a little more explicit than just generalizations, to a degree, but you're going to find two things the more you study them, in particular with the identity of Jesus Christ:
1) He still looks quite a bit different in other ways and really does come looking like their gods, but completely defying the mold at the same time. He is God descending to become man, and saving His people through a selfless death and resurrection that lifts him up to Lordship over the heavens and the earth. That story is unique.
The stories are a based upon one another and developed throughout centuries side by side. Any rational person would expect the stories to be similar given mankind's cultural development and the development of these religions throughout history.
2) If we would say that just because two religions have similar images or themes, one must have come from another, then we simply can't explain the history of religion. These connections and themes are literally global. By making this argument against Christianity you would really, eventually, have to argue for one common mother of all religions, but that wouldn't really work very well with the rest of your worldview.
The Hebrew creation story certainly takes aspects from other civilizations as well. The Egyptian example is one of many and I used it just to throw out an easy, simple example. As for their similarities:
Already been dealt with from a previous thread.