So the Lord God caused a deep sleep to fall upon the man, and while he slept he took one of his ribs and closed up its place with flesh; and the rib which the Lord God had taken from the man he made into a woman and brought her to the man
Exodus iii, 14
God reveals himself to Moses as: “I am who I am.”
“I will be your God, and you shall be my people.”
One the one hand they don't believe in God's awesome power and abilities as demonstrated when He made woman from the man. Then on the other hand they believe that God is all-powerful and can do anything as He is "I am who I am" . No wonder their "cult" is such that it is: they are going against one of the first commandments of the bible, to not lean on your own understanding, but to obey God and Him only.
The whole bible is the Word of God, even Genesis. That is how God really created people, the earth, the heavens, etc. To call yourself a Christian and not believe that, you are really not a Christian. A real Christian believes in the bible from Genesis to Revelations, period.