I've been on think atheist for quite some site now, and I've noticed that because the vast majority of people here are ex-Christians, naturally the New Testament and Jesus get the most attention.
As an ex-Jew, I've decided to write a post explanation of what Judaism is, as I've found practically no reference to this question here.
So here it goes.
While Christianity believes that God- Yahweh, brought the people of Israel to mount Sinai and gave them the old testament- the Jewish religion in it's entirety is founded on the basic concept that Moses received not one- but two texts at mount Sinai –the written bible (the old testament) and the oral bible.
The belief, as it's described in the Talmud, states the following: God wrote the Torah (The old testament) before the world was created, and as such it contains the entire knowledge of the universe hidden inside it. Moreover when god dictated the torah to Moses he gave him letter after letter, as a mass of incomprehensible text. The decision where to place spaces between letters, thus forming words, was a human one. Thus, the text is godly, and can never fully be comprehended by man. Man cannot understand a text made by god, let alone when man split the letters into words.
Furthermore- Judaism states that the one and only reason God had for giving the people of Israel the Torah- was to teach them a godly judicial system of law- called the Halaha. Each law is called a Mitzva, a godly law, written or derived from the Torah which binds the Jew.
All the stories- all of them, be it Genesis, The exodus, Kang David and so fourth- are nothing more than a literary foundation for passing the heavenly law – the Halacha- to the Jews (and the Jews only I might add…)
But as I said before, the bible cannot be comprehended by man- so how do you derive a system of justice from the text? Well- that's where the oral torah comes in, given to Moses on mount Sinai along with the written one.
Let's take a brief break for some actual history. There is not a word in the bible about a second oral torah. We do know from the Jewish roman historian Josephus, and the New testament, that in the time of Jesus, there existed two major Jewish sects- the Sadducees, and the Pharisees.
While the Sadducees believed only in the written bible, the Pharisees claimed to have an oral tradition as well- passed down from Moses. This sect was to eventually take over Judaism completely- and make it what it is today, and has been for around 2000 years.
In around 200 AD, after the second temple was destroyed by the Romans, a prominent Pharisee Rabbi, named Rabbi Yehuda haNasi, took these oral traditions, which supposedly passed only by word to mouth completely unchanged for over 1000 years, and edited them (without writing them down) into a compilation called "The Mishna". The Mishna is essentially a book of law, very dry and straight forward, where you'll find verse after verse of legal statements.
For instance: "If a man cleans his house and get's rid of all the bread for Passover, and a mouse enters his house with bread in his mouth, the house is no longer kosher and must be cleaned again" (Masehet Passover, page 10)
Later, sitting in the exile in Babylon, rabbis examined the dry laws on the Mishna, expounding on them greatly, in a work of literature called "The Talmud". On every single law stated in the ,Mishna you'll find pages upon pages of deliberations in the Talmud, examining the judicial issue from every angle. For instance, "what if not one mouse, but rather two, enter your house? What if it's a rat? What if the rat eats the mouse and the bread? Is your house still in need of inspection?"
The Mishna, expounded on in the Talmud meticulously through every walk of life imaginable- legislating the life of the Jew from dusk till dawn. Sometimes the texts refer to the written torah, and sometimes they ignore it. Sometimes the Talmud openly contradicts the torah, and takes precedence over it.
Back to Mount Sinai – while it may be clear to any reader that more than 1000 years span between Moses on mount Sinai (if it ever existed…), for the religious Jew- the Mishna, and the Talmud deliberating the Mishna - are all actually the words of god given to Moses at mount Sinai.
Just as the bible is no more than a figurative tool for explaining a judicial system of law to the Jews, the Talmud, written in the form of fifth century AD rabbis deliberating back and forth over seemingly trivial judicial issues, are only a literary tool which god used when he dictated the Jewish code of law to Moses in 1400 BC…
And it gets even weirder.
There are many places in the Talmud where the oral torah contradicts the written one. For instance, the bible prescribes 40 lashes with a whip for offenders, while the Talmud states 39. Imagine the scene- God dictates the Written torah to Moses on mount Sinai and says: "Moses, write down that offenders are to be whipped 40 lashes. Then god say's "Moses, I didn’t mean 40, I meant 39. Don't chance the texts, and don't write down 39- just remember what I told you, and pass it orally. It will eventually be written down in around 1000 years…"
And this is only one example of many. This is Judaism.
A very interesting past of the story is that the rabbinical Judaism, and the compilation of the Talmud happened parallel to the formation of Christianity.
In effect, the real Judaism is lost forever, and what we have today are two "New Testaments" - one Christian, the other Jewish, both about equally as old, claiming to be the "Real thing".
It's amazing to see, that when a Jew has a theological question, and as the Jew's life is completely regulated by the Talmud, he lives in a constant fear of braking god's divine laws- (such as which shoe lace to tie first- right or left) and always has theological questions, he'll go to a Rabbi, and the Rabbi will look for the answer- not in the bible, but in the Talmud.
As I've said, the bible is worthless. It's completely incomprehensible as a practical codex of law. The Jews worship it as god's book and read from it in the synagogue, but when they have a question, they turn to the Talmud- god's manual on how to live.
That's it for now. If this interests anyone, I'd be happy to share more of what I know about this topic.