So I’m really trying to research this honestly. I even…

So I’m really trying to research this honestly. I even went to a Jewish group, but they’re not very helpful all they keep doing is accusing me of being a wolf in sheep’s clothing when all I’m trying to do is find the truth. Super unhelpful and frustrating. I thought they would actually have more resources.

How do we know that Judaism and the entire OT is not a product of outside religious influence? I’m studying ancient history and many secular scholars assert that Judaism is in fact a religion that is a product of many ancient religions and even Greek gnostic influence. How do we know it was the other cultures that took from Judaism or the Hebrew beliefs and not the other way around? Please provide sources. Thank you in advance.