Yeah, I have to agree with Harm on this one. I've never been a fan of the whole concept of Original Sin. I never liked the idea that because of a sin Adam and Eve made at the beginning of human history, a baby fresh out of the womb will go to hell, if not baptized as soon as possible. The poor thing hasn't had a single chance to be mean or violent to anybody. That's not fair at all. That was, in fact, one of the breaking points for me, when I decided to not be a Christian any more.
While I agree that blaming God for such things is useless, I similarly feel that blaming two idiot humans from deep in the mists of human history isn't fair either. That includes the interpretation that the story is really about the two primates that decided to come down from the trees to grasp at the blossoming flower of full sentience and evolve into the first humans, who gave up the idyllic life of being animals living up in the trees. I hardly see that as a sin, much less one I have to pay for.
And as for the angel wars, surrounding Satan, that's a fascinating read, and not wholly contained in the Bible. Here's the short version. The Angels were god's first creations, and were faithful followers, with unquestioning loyalty. Lucifer, morning-star, bright one, a heavenly general and most beautiful of God's angels, became jealous that the Humans, which were created in God's image, did not love God perfectly, and were still somehow God's favorite above the Angels. This became an argument between him and God, resulting in Lucifer falling from Grace, and being kicked out of heaven. Some of the Angels that he commanded, and a number of others that felt the same, followed him to Earth, and together they actively started working against Heaven, starting a battle that rages to this day, and in response, God exiled them from Earth entirely, creating Hell. I don't know how much of it I could believe, but it makes for a good story.
The pre-cursor to the Jewish religion was actually one of the Mesopotamian Angel Cults (worshiping angels), and that's where some of the details of the story come from. Here's some starting place for that:
Ancient Mesopotamian Religion (Wikipedia)