@z0z0,
The Torah is the Old Testament. Many other documents were also kept such as the Apocrypha (which was actually still in many Christian Bibles until 1880) and Rabbinical stories made to expand on Biblical characters who's back story wasn't covered by the Bible.
There were actually 3 Torah at one point, one was Babylonian, another Egyptian and the third... well I don't remember exactly where it was.
The concept of Original sin doesn't appear in the Torah, it was purposed by Jesus and it was solved by salvation. Jew's believed in atoning for their own sin, and didn't (and still don't) believe that it's impossible to live within the rule of God.
Orthodox Jews still follow the covenant, while the majority explain away the need for it even though their Holy book doesn't make any such claim.
Early Christians also believed it was a sin to create Idols, in fact the idea of looking upon a giant cross or idol of Jesus on the cross would have been blasphemous to them, that lasted right up until the creation of the Universal Church.
I'm surprised a Christian isn't familiar with the OT, Jesus was extremely familiar with it, aren't Christians supposed to do as Christ did?