The bible contains sumerian mythology

The Veda are one of the oldest religious texts found on the planet. It influenced many other religions around it like, Christianity, Judaism, Islam, Sumerian, and the Egyptian religion. In Christianity followers say "Amen" at the end of their prayer, it was the same with the Egyptian religion. Christianity, Islam, and Judaism are also quite similar. All of these religions were influenced by The Veda and many else were too, I urge you to read at least some of The Veda, they are deeply related to many religions if you look at the texts intelligently.

My two cents worth.

It's only an intuition of mine based on cursory and scattered reading in these areas but I believe that two famous old cultures, that of the Greeks and that of the Jews had something in common, a tendancy to absorb material from other cultures and then cosmetically change it and call it their own.

The Greeks are highly indebted to the Egyptians for both religious and scientific ideas, I think.

The Jews are indebted to both the Sumerians and the Egyptians. My own feeling is that the Jews are undoubtedly cultural relatives (perhaps a subset) of the Sumerians with their own core tribal beliefs, heavily overlayed with more elaborate and complete Sumerian ideas, which were reshaped and abbreviated when the political opportunity arose to do so.

I don't think these old cultures regarded each other as being as different from one another as we think of them being different today. In fact denying cultural influences from another group, when they must have been obvious to anyone then as now, was probably essentially a political act.

In Herodotus, that notion of familiarity with the neighboring cultures and a very relaxed attitude to them (undoubtely based on recognition of common elements within one's own culture) really comes through.

Politics doesn't seem to be cultural in Herodotus, but rather personal, as it might be between competing mafia families for example, even though the competing families in question might control separate countries.