So my question is: why does "God" refer to himself in plural? (Let us create...)
I did some research, and the Trinity isn't even mentioned in the Bible (at least not as "Trinity", there are hints of it). Why would a "God" that claims to be only God refer to what looks like others like him (as if he was one of many; "our likeness")?
*I'm an atheist (just in case)
God is like the Chairman of the Board of a huge corporation that is comprised of many specialty companies. He has other people, who are the CEO's, in charge of day to day operations for each company. God will do Plant visits to meet with his top people; Book of Job.
A smart God first forms a chain of command, so the many tedious things, in the works, can get done, as the big guy plans the next steps. This is why Angels, Lucifer/Satan and the Son are already there.
You first build a good team and then you enter the arena of creation. This diversity of CEO's and companies, explains why things are not perfect, but closer to complete; good and evil, male and female, hot and cold, life and death, etc. The Chairman of the Board heads the steering committee, and he has faith in his teams as he plans the future with bigger goals. Jesus said; to paraphrase, nobody has seen the Chairman except the son; CEO and whomever the CEO takes to meetings; plant managers.
The mistake often made is to assume God is a loner, and did not think ahead to create company for himself, and to make his job easier and more efficient; planning stage. Humans want to believe God, the Chairman of the Board, is assigned to them, alone, since they are so so important. Satan and then Jesus were destined to be their CEO's.
There are now more important fish to fry, like making preparations for the new heaven and earth; Revelations. That takes a lot of planning and may require a new batch of CEO's or they're reeducation, which also needs to be planned. When God says "we", he honors his teams.