It was clear early on that we ought to retell the Parable of the Prodigal Son, Brennan's favorite story. We agreed on a central character, Jack Chisholm, who would be our focal character, and we agreed that his fall from grace—and his recovery and change for the better—would be our topic. After we'd agreed on the story and central characters, it became my task to flesh out those characters and bring them to life on the page. I think this is a good analogy: Brennan and I designed a house together. Then I had to build it and decorate it with his stuff. People who have read my first three novels will see how very different that process makes The Prodigal—and yet how many themes from my earlier work reappear in this book.

You speak of Manning's thoughts of grace in your Patheos article about his death. How did his personal experience with grace, as well as your experience of it, drive this book?

Folks who know Brennan respond, I think, as much to the man as to the work. He was someone acquainted with failure but brutally honest about those failures as a husband, as a priest, as a person of faith, as a recovering alcoholic. What made it possible for Brennan to keep going was his perception of God as a God of grace who forgives before we have even asked, as in the story of the Prodigal Son. Like Brennan, I have failed more than my fair share of times, and yet here I stand today, not only alive, but joyful, forgiven and welcomed back into communion with God, humanity, and myself.

I believe grace is central to the Christian faith because I too wouldn't be here without it, and I don't think Brennan could have gone on for so many years—or have touched so many people through his teaching and his life—if he hadn't been extended that grace as well. So as authors, we wanted to extend that grace to Jack, and we also saw it at work in the character of Father Frank and others who had been broken but experienced the grace and forgiveness that allowed them to love and forgive others.

How did your perception of the prodigal son story alter after you became a father?

That question reminds me of a poem by my friend Scott Cairns, "The Spiteful Jesus," in which the speaker compares the prevalent figure of the angry God with the speaker's own earthly father:

I made him [The Spiteful Jesus]
for a corrupt, corrupting fiction when
my own father (mortal that he was)
forgave me everything, unasked.

I love my children—my boys, my girls—and like the Father in the Prodigal story, I would set out to meet them, to welcome them home, even if they had hurt me badly or offended my sensibilities. That kind of love is countercultural, counterintuitive, and hard to understand when you're a single person. I don't think I had any idea what real love was before I became a parent, but that extravagant love explains the story of the Prodigal—and of the God who loves us—in ways that are understandable because we can extrapolate from the human to the Divine.

In this novel, you made the father character more realistic than in the parable. What were your motivations in altering the story?