This isn’t where we part company. Where we part is in our definition of being a Christian.
Jews know the Creation story. But we have Jesus.
I would correct this statement (because, again, you are limiting Christianity to only the New Testament)... Jews don't know Jesus, but we embrace our full heritage in the family of God.
Our story begins at the beginning. The New Testament is forshadowed in the Old and the Old is fulfilled in the New. Without the New Testament, the Old Testament is just a narrative and it's unfulfilled. Without the Old Testament, the New Testament lacks context... that's why so much is referenced back.