The claim was this:
"If God were real, you wouldn’t need a book"
Which is true when you're talking about a man-god as Christians claim exists. If the god of the Bible were real, there would be evidence to support its existence and the Bible wouldn't be necessary.
That's why I use to example of wiping all books about the Christian god off the face of the earth and wiping all memories of Christianity from peoples' minds. If that happened, Christianity would cease to exist there is no evidence for the Christian god to revive Christianity.