my apologies if I offended you, it is my understanding from how you described a deist as very close to agnostic (hence the ish).
Sumeria is probably the oldest and first group to move from hunter/gatherers to an agrarian society.
Sumeria is no longer considered the oldest, by several civilizations. But that really isn't that important
There is no mention of Abrahamic beliefs in their theology. Many other pre-Abrahamic civilizations as well. So my question stands. If what JC had to say was to important to mankind, why did he let thousands of years of civilization pass before he chose to come down and set them straight?
While I understand your argument, and could agree from a physical evidence only way of thinking, I have to disagree with the idea. There are probably 1000s of possibilities for these ideas. 1 being pre-flood Noah (PBUH) the righteous and believers were much fewer. To the extent of 1 family for many generations. There wouldn't have been a society talking about God during this time. (Biblically this was 1000s of years, with possibilities of much longer in reality) after that point the Abrahamic believing people (obviously not Abrahamic at this point as Abraham (PBUH) hadn't been born yet) still were not a large group. Sure it talks of some towns here and there, but these were probably 2-3 families (maybe 30-40 people), and beliefs were probably scattered even in these groups. These were brought back in line when Abraham (PBUH) began his Prophethood. (about the time we see recognizable symbolism in historical records) Everything here is still oral traditions, and writing wouldn't have been a likely source without proper instruments and medium. It is said a few generations later that Moses (PBUH) began recording these traditions and was revealed the Law (Torah). (This is still a smaller community, but the size is growing to where we can start recognizing it more readily).
As I stated, this is only 1 option, and you are correct that statistically speaking, it is very possible we are wrong. I have no qualms with that assessment, I have faith, based on what I have read and witnessed and what I read and confirmed.
And while I am at it, here's another conundrum I have. If the Abrahamic traditions are really that important, why did they only give the scoop in the Middle East? Why ignore the ancient Americans. Or the Far Eastern cultures. Or the Oceanic ones. If it was a message for all mankind seems to me it should have been given to all mankind!
This is a perfectly reasonable question. Of course I would have to give you the Islamic perspective as that is what I believe. We see the same principles pop up in most world cultures over time. Teachings of Buddha closely resemble the teachings found in Bible in many points. The Ideas of Hinduism are mostly congruent to those in Islam, to the point that some believe in 1 God (I am told it says this in vedas that the other "gods" are just different forms of the 1 God). Most religions of the world agree on a large portion of Abrahamic laws and beliefs (each different in their own way). From Islam we attribute this likeness to the source of each of these religions being a Prophet of Allah. And their teachings were the same as the Abrahamic prophets, but corrupted over the years. Their societies didn't spiral into chaos like those of the Middle East (center of the world at the time in terms of trade locations etc.) There are evidences of Judaism in some Native American cultures to the point that they referred to themselves as Jews and had rough copies of Torahical texts.
As for the last comment, it had to be delivered to someone. Torah states that it had to be from the Abrahamic line. Could he have sent the Quran to multiple people at once, probably. But as we believe that in the end of days all will be flocking to Islam, it wouldn't have allowed as many souls to find their way to Heaven (Jannah, Paradise, etc)
Only the Writings have authenticity for us.
I would say there is a large movement in Islam that is going this route with Quran. They use Hadiths as more suggestion than rule.