The "Garden of Eden" story first appears in the Gilgamesh Epic, which was the creation story in the Baal religion. You may remember that early Christians existed along with other religious beliefs and the Baal religion was referred to as a religion of idol worshippers. Since the Gilgamesh Epic predates Christianity by about 1000 years, most bible scholars credit this as the actual source of the Christian creation story.
Ethical teachers have existed throughout human history. Some of those ethical teachers are said to have been the product of unique birth. ( Budda's mother was a white elephant)
Humans living in social environments require control of group and individual behavior. The control includes laws, customs, traditions, mores, and religion. In the case of religion, the goal is an ethical population of like-thinking individuals. The idea that ethical laws are handed down by a diety is quite common, its hard to argue, and the true believers amass a body of rhetoric allowing them to argue their point just as the non-believers do. No matter which side of this you're on, the evidence you have accepted is convincing to you. Ethnocentrism, a universal human characteristic, adds fuel to the debate without adding evidence to the discussion.
We are only monkeys with digital watches
and chemically enhanced crotches,
keep an open mind...........