BTW - Everyone has a book, a text, a worldview with a set of beliefs, that undergirds their moral beliefs and interpretive framework.
But... few have examined their own worldview.
But... philosophers specialize in this. They follow Socrates' counsel that "the unexamined life is not with living."
So... followers of Jesus... no need to back down when your belief in The Book as our authoritative text is ridiculed or dismissed. I suggest asking the crticai this: "So what's your text?"