The Bible never mentions Christianity. It does not preach Christianity, nor does it encourage us to preach Christianity. Paul did not preach Christianity, nor did any of the other apostles. During centuries when the Chruch was strong and vibrant, she did not preach Christianity either. Christianity, like Judaism and "Yahwism," is an invention of biblical scholars, theologians, and politicians, and one of its chief effects is to keep Christians and the Church in their proper marginal place. The Bible speaks of Christians and of the Church, but Christianity is gnostic, and the Church firmly rejected gnosticism from her earliest days.
I can only hope that this has whetted your appetite for the rest of
this fantastic book! I am sure I will be quoting from it frequently in the coming weeks and months. I bought a copy of the book a couple of weeks ago. The day after receiving the book I had finished reading it. If you want a very small taster, read Peter Leithart's original article,
Against "Christianity": For the Church.