How ancient is Judaism?

At some risk to my "Goy" self, I occasionally write something about Jews and Judaism. So far, however, I have escaped unscathed (I think) so here goes another foray:

It is a common and proud claim among Israelis that they are still living in the same place and speaking the same language and (sort of) following the same religion as they did 3,000 years ago. That thought gives them great pride and helps make up in some way for the horrendous travail Jews have had to go through to get to today.

But, to be blunt, it is nonsense. After the Roman triumph and the expulsion of most Jews from Israel, Jews had to change their religion radically. Judaism had been a temple-focused religion -- so once the temple was gone, huge changes in thinking and custom were needed.

And the changes took two forms: Those who accepted the ideas of the greatest rabbi (Jesus Christ) and those who laboured to stick more closely to traditional ideas. Even among the latter group, however, the surrounding pagan culture took over to a degree. The modern form of the seder, for instance, is said to be strongly influenced by the form of the Hellenistic symposium.

So Judaism as we know it today is in fact no older than Christianity. They are two branches that had to put out fresh growth after the original tree was cut down. And just as Christian thinking underwent all sorts of disputes in its development (e.g. the Arian/Athanasian controversy) so Jews waited a long while for their new ideas to coalesce -- in the form of teachings by great rabbis such as Rashi and Maimonides.

Christian thought in fact probably coalesced more rapidly that did post-temple Jewish thought. Rashi and Maimonides both wrote over 1,000 years after the fall of the temple but have been immensely influential. And by the time they wrote, they lived in a Christian world so were undoubtedly influenced in various ways by Christian ideas -- and Christianity had itself taken on a pretty heavy load of pagan ideas by that time. So I am sure that the Christian/Egyptian concept of the triune God was the subject of much private hilarity among Jews.

So we in fact have two religions of ancient Jewish origins that are quite contemporaneous -- with the Christian variant more successful in most ways. And while Christianity/Judaism precede Islam, Sikhism and Bahai, they are themselves preceded by Hinduism, Buddhism, Confucianism, Taoism and Shinto. And I'm inclined to think that Shinto has the best hats -- despite formidable competition from the gold crowns of Russian Orthodoxy and the shtreimel of orthodox Judaism.

I guess I'll get a few zingers over all that! I'll hear about the Talmud and the Midrash and so on. As an atheist who is sympathetic to religion, however, I may be in a position to be more impartial than most.