[quote="cargau, post:13, topic:333452"]
The Trinitarian dogma was not defined until long after Genesis was written. The truth is, monotheism was not completely accepted in the beginning. The Jewish people were likely in bondage when Genesis was written. No doubt they were influenced by the other near eastern cultures that preached a theology of polytheism.
Also, consider that those who lived in that part of the world were agrarian. There was no irrigation systems and they depended on god's like Baal, the god of fertility including rain.
I can assure you that the Scripture writers had no knowledge of the Trinity. Remember, the fullness of revelation is still not complete, but the greatest of revelation surrounds Jesus of Nazareth. The writers of Genesis had not the benefit of this revelation.
Since the Jews didn't believe in the Trinity back then (obviously), writing "us" implied something else then. I think it goes back to what the New Jerome Commentary suggested: there was an ancient tradition of belief in mysticism (like other parts in the bible) that are written. The two "us" verses, cherubim, "you'll be like gods", etc. The "us" would mean a divine assembly then, and tradition was that of several gods who were in this assembly to decide the fate. However, what's powerful about Genesis and its theology the first 11 chapters is it puts only one God (Yahweh) as the decider.
When Christ revealed the trinity, it made us see Genesis in a new way. Let "us" would have been later considered a trinity reference. The intentions for writing "us" as the author did had no knowledge of the trinity, so I tend to think it's a matter of assimilation of old mysticism and taught how God acts alone.
There was a book that the early Christians read called Enoch. It had a lot of mysticism in it too but told the story of God. It had to do with giants, etc. So, there was an assimilation of old mysticism, as with the "us" verses, and the later understanding of the trinity because God did not reveal it to them yet. I do agree we as Christians can interpret the old testament with better understanding now which did show references to the trinity. So I don't think the commentary contradicts church teaching on the trinity, but rather gives a background understanding.
I do find it interesting how scripture refers to the book of Enoch since the early Christians had this writing, but it's not in the bible. I guess that's another topic :)