Ok…I’m going to try and give some elements about the evolution of the Hebrews’ religion. However, first I’m not really aknowledgeable about this issue, and second I don’t have any reference documents handy (or more exactly, they’re lying somewhere around, but I can’t find them. So, take what I’m going to write with a grain of salt. I hope some other posters will come and give more accurate infos.
The people who wrote the bible are generally considered as being a mix of two people : the nomads whose story is supposedly told in the bible (Moses, the conquest of the promised land, etc…) and who took over the land which would become later the kingdoms of Israel and Juda, and the sedentarized people who lived previously in this area. Their culture and religion were a result of this mix.
The “hebrews” brought with them YHWH. You’re wondering about his origin, but unfortunately, AFAIK, the answer to this question isn’t known. Generally speaking, we don’t know much about the origins of the religious beliefs existing during this era, and it’s even more difficult concerning a people which was small numerically and not literate. Actualy, not only the religion, but even the origins of the Hebrews are for the most part, unknown. The only sources are : the bible, which certainly contains part of the oral tradition of these people, but which has been written quite late, by people who had a religious agenda corresponding to a system of belief which evolved a lot meanwhile, and archeological evidences which are scarce.
However there are theories about the origins of YHWH. But only theories. Nothing is proven, because, once again, we lack unquestionnable evidences. For instance, based on some archeological finds and on the history of religions in the middle-east, many believe that the Hebrew followed the path polytheism —> henoteism (already defined : only one god is worshipped though the existence of other gods is aknowledged) ----> monotheism.
There are hypothesis according to which YHWH was originally a “moutain god”, worshipped by the local tribes. But I never found the evidences used to back this theory very compelling (now, I’m not a specialist at all, so perhaps they are more compelling that they apear to me).
An example of such evidences would be that there are archeological proofs that several moutains were places of worship, probably including pilgrimage. Since Moses is said to have “met” YHWH at the top of a mountain, YHWH could have been one such “moutain god” (or god worshiped or moutain tops). Now, once again, there’s probably more to these hypothesis than that, but they appear to me as being…well…only hypothesis about something it’s unlikely we will ever find definitive answers.
So, the invaders brought with them YHWH. Perhaps a moutain/storm/whatever god. Or perhaps not. Perhaps one god amongst many. Perhaps already an henotheistic god. Perhaps the the main god of a particular tribe. Nobody knows for sure.
Now, what was the religion of the sedentary and city-dwelling population which was subjected to the Hebrews? Most certainly, extremely similar to the religious system existing at this time in the middle-east. This system was polytheist, but advancing quickly towards henotheism. Cities had a main protector god, who had slowly “swallowed” the attributes of other deities, which were becoming more and more secondary figures, not really worth any serious worship.
Baal, for instance, was one such god (note by the way that the was actually several Baals, since two different cities could have different “versions” of him. He could even be worshipped under have several “aspects” in the same place. There are references to “The Baal of (whatever)”, for instance). Apart from Baal, a similar deity was the father-god El, worshipped in many places at this time. This one is particularily interesting because it seems that it’s this deity which was “merged” whith YHWH to give birth to the bible’s god. The name “Elohim” (plural of El) as already been mentionned in this thread.
Once the hebrews had settled and mixed with the local sedentary population, it is quite clear that there has been a period during which henotheism prevailed, at least amongst some elite (polytheism could have prevailed amongst the populace) . There are evidences of this in the bible itself (verses which don’t seem to refer clearly to an only true god , but rather seem to imply that YHWH is the only god the hebrews should worship, and of course the many condemnations of idolatry, worship of other gods, etc…which imply that said worship/idolatry was rather widespread).
The main god El/HYWH, according to some, could have been originally the “protector god” of the royal house becoming latter, after a significant theological switch, the god of the Hebrew people as a whole. Or, as I wrote, it’s possible that the “system” was already essentialy henoteistic and that this god’s cult was largely widespread essentially from the beginning. In any cases, other gods were still worshipped for a long time, as proven by the bible itself.
And these other worships weren’t only surviving amongst the “ordinary joes”. It had obviously some recognition. An evidence of it is the surprising request, at a late date, by hebrew mercenaries stationned in Egyptia, adressed to the Jerusalem temple. They wanted to be allowed to build a shrine to worship YHWH, of course, but also his Asherah (likely his spouse, or at least a companion deity) and other gods. So, it seems that these Hebrews thought that Jerusalem was the ultimate authority concerning the worship of various deities, somewhat directly related to HYWH. From this, one can deduce that even the religious authorities at least aknowledged these gods, and possibly were in charge of their worship.
Remember, by the way, that the bible, in its final form was written at a quite late date, and though it certainly still included parts of the former accounts and traditions, these have been largely twisted towards the religious stance of the moment. So, one has to dig through it to find the footprints left by earlier beliefs.
The major breakdown came with the fall, in succession, of the two jewish kingdoms, Isreal and Judah (kingdoms, which, by the way, already had some theological disagreements), followed by the exile to Babylon.
It’s at this moment that the Hebraic religion took its final shape. In particular with the utter rejection of idolatry, since the fate of these kingdoms was attributed to their lack of faithfulness to their god. But also with the influence on the exilees of mesopotamian religious concepts and beliefs, in particular the dualist zoroastrianism. I read very informative posts and links regarding this influence on the SD board, so I hope that some posters with a good grasp of this issue will post in this thread.
Once again, all of this is just out of my head, so don’t be too harsh on inacurracies.
(All of Michener’s books are fiction, but give a good history of whatever he writes.) Basically, different peoples had different gods, and they all had many gods, but one god among them was supreme. The pre-Jews believed their supreme god was better than all the others, particularly vis a vis Baal, which was the supreme god of their neighbors. In the beginning, many of these inchoate Jews believed in plural gods, but YWHW was above all. That is the reason (or one of the main reasons) why YWHW told Moses that thou shall have no false idols: that I Am That I AM is the one and only God.