Well, the book of Genisis you mention is from the Old Testament, which was written BEFORE Christ, therefor before “Christianity”...Which, of course, is so named because of Christ...
Wait. Are you dismissing the entire Old Testament? Christ is a product of the Old Testament. All of Scripture — including the OT — points to Christ. He is the fulfillment of the OT.
Jesus believed the OT. Referenced it all the time. If it’s good enough for Him, it’s good enough for me.
Technically, that is not correct.