Why Judaism?

Hello everyone this is just a discussion/question from an atheist, I am not attempting to offend anyone or undermine any religion whatsoever so please do not hate me for whatever reason. Anyway.

I think that an atheist and a theist can go back and forth forever but even if the theist can prove the existence of a God it does not prove which God. Is it the God in Judaism, Islam, Christianity, any of the other religions out there or is it a God not from any of those religions at all. It’s to my understanding that the Torah is the first 5 books of the Hebrew Bible; Genesis, Exodus, Leviticus, Numbers and Deuteronomy (please correct me if I’m wrong) and in my personal experience I have not met any religious Jews who truly believe in the Torah word for word due to the fact that many of the stories (Genesis for example) goes against our current scientific understanding of the world and many of the laws laid out in the other parts of the Torah are very brutal. For example Leviticus 21:9 (Hebrew Bible) “If a kohen’s daughter becomes desecrated through adultery she desecrates her father; she shall be burned in fire.” Personally I think that’s a harsh punishment for adultery. My point is, if you do think some parts of the Torah are untrue or shouldn’t be followed then why should we believe in it as a whole if some parts are inaccurate? In my personal opinion that points more toward a human writing this compared to the word of God. Again, I do not wish to offend or insult anyone or their religious beliefs whatsoever. I really wish to be proven wrong.