This is an interesting an important point, not least of which because of its implications for the origins of Gnosticism.Genesis 1-2 further distinguishes between the god who created the cosmos and the god who created mankind, thus absolving the highest god of responsibility for the sinful nature of humans. Other authors of Pentateuchal books evidently disliked this polytheistic-tolerant concept and worked at conflating the two gods into one -- a "purer" form of monotheism, and a monotheism that expressed no tolerance for any thought of other deities hanging around.
But I'm struggle a bit with this claim.
In Gen 1 we see only "God" in the modern Old Testament text. I presume this was originally "Elohim"?
This account, however does not include any fall.
The wording of v26-27 is very strange. As Philo points out, it implies a separate maker who is unmentioned. Philo attributes the making of man here to the Word. Who is "Us"? Who is "He"? "in the image of God He created him" implies that someone else created him in the image of God. Again, Philo explains this inferred other being as '"the Word".
But importantly, in Gen 1, it is God to creates man(though there is the implication of another being) and, "God saw all that He had made, and behold, it was very good."
Then we come to Gen 2, and in Gen 2 we are now presented with "the Lord God", which I presume is YHWH-Elohim.
But in this account YHWH-Elohim created both the heavens and the earth and humans.
So in Gen 1 Elohim creates everything, including people and in Gen 2 Yahweh creates everything, including earth and heaven and people. So I don't see a distinction here between, "the god who created the cosmos and the god who created mankind". It seems that one account attributes it all to Elohim and the other attributes it all to Yahweh, but we don't have an account that attributes the creation of the cosmos to Elohim and the creation of man to Yahweh.
Interestingly, in Gen 3, we are told, "8 Now they heard the sound of the Lord God walking in the garden in the cool of the day, and the man and his wife hid themselves from the presence of the Lord God among the trees of the garden."
This does perhaps imply an original story in which it was Yahweh who was walking in the garden. I could envision a narrative in which it was originally stated that that Elohim created the cosmos and Yahweh created Adam and Eve, and that Yahweh was walking in the Garden. But that's not what Genesis actually says. And if we were it imply such a distinction and such a tale, it would imply a pre-existent Israelite story, not a Greek or Babylonian story, lying behind Genesis 2-3.
Further still, when we get to Genesis 4, we find only the Lord, YHWH.
6 Then the Lord said to Cain, “Why are you angry? And why is your face gloomy? 7 If you do well, will your face not be cheerful? And if you do not do well, sin is lurking at the door; and its desire is for you, but you must master it.”
This fits with the expectation that Yahweh was a son of God who often came to earth an interacted with people on behalf of his father. In original Canaanite/Israelite lore we could expect that there were stories in which Yahweh met with leaders and negotiated with them on behalf of his father El, Yahweh joined the Israelites in battle, Yahweh was sent to earth to mete out punishments and rewards, etc.
But what are we to make of all these changes through Gen 1 to Gen 4? Why were these distinctions between Elohim and Yahweh being made in this way? Does this not imply that some Canaanite/Israelite stories lie behind these accounts?
Did the writer of Gen 4 see Yahweh as distinct from the Elohim of Gen 1? What about the writer of Gen 2-3, who gives us Yahweh-Elohim? At no point do I see a clear distinction between a supreme God and a separate craftsman as Neil seems to have stated.