In the Author's Note at the end she describes her return to Christian faith after many years away. She also describes her research for the novel during which I was delighted to find she is an NT Wright fan:
one of the most brilliant writers I've ever read, and his generosity in embracing the skeptics and commenting on their arguments is an inspiration. His faith is immense, and his knowledge vast. p318
Rice's research involved much reading of those skeptical about Jesus until:
I became disillusioned with the skeptics and with the flimsy evidence for their conclusions, I realized something about my book.
It was this. The challenge was to write about the Jesus of the Gospels, of course!
Anybody could write about a liberal Jesus, a married Jesus, a gay Jesus, a Jesus who was a rebel. The "Quest for the Historical Jesus" had become a joke because of all the many definitions it had ascribed to Jesus.
The true challenge was to take the Jesus of the Gospels, the Gospels which were becoming ever more coherent to me, the Gospels which appealed to me as elegant first-person witness, dictated to scribes no doubt, but definitely early, the Gospels produced before Jerusalem fell—to take the Jesus of the Gospels, and try to get inside him and imagine what he felt. p319-320
Which is exactly what she's done. An act of literary worship, in fact. It'll be going in the StB library.