You really didnt think this through…
Everything was the same, except we had more mitzvos then all 613, we had a bais hamikdosh, we were in EY and we had neviim. There was no permission to write Torah Shebbal Peh (the Gemara) down however Gemara Shebal Peh was learnt (minus all the parts from machlokesim of Tannaim and Amoraim because this was pre Machlokes Era)
We are still the same nation descended of the same people from then keeping the same Torah (whatever still applies bizman hazeh) but we are in Galus and have been minimized. Hopefully soon Moshiach will come and we can reclaim our former glory.