In a 2017 interview with Port Magazine , he touched on this residual faith: “I believe in the potential for human goodness. I believe that we are more than just the sum of our biological parts. Whether you call that a soul or a spirit, I don’t know. But I feel it. I felt it when my father died.” The death of his father, Kent, in 2017 from cancer was a turning point. Damon spoke of being in the room, of watching the moment when his father’s consciousness simply… stopped. For a materialist atheist, that is a biological event—neurons ceasing to fire. For Damon, it was a mystery.

Consider his work with Water.org, the non-profit he co-founded with Gary White. Since 2009, the organization has provided access to safe water and sanitation for millions of people. When Damon speaks about this work, he doesn’t frame it in secular humanist jargon. He frames it as an obligation . It is not merely “good to do.” It is wrong not to do. That is a theological distinction: the difference between a preference and a sin.

This is a strikingly conservative insight from a liberal actor. It reveals that Damon’s agnosticism is not a rejection of religion’s utility. He understands that faith is not just about God; it is about practice . It is about kneeling, singing, lighting candles, sharing bread. These acts shape the self in ways that rational argument cannot.

Consider his role as the priest in Martin Scorsese’s The Departed (2006). It is a small, chilling scene. Damon’s character, Colin Sullivan, a corrupt cop and a mole for the Irish mob, goes to confession. He tells the priest he has committed sins “that can’t be forgiven.” The priest, played by Damon, leans in. The camera holds on his face. He looks compassionate, weary, and utterly convinced of the sacrament’s power.

Damon has never hidden this foundation. In interviews, he speaks of going to Mass, of the rhythms of the liturgical calendar, and of the moral grammar that Catholicism instilled in him. He attended Cambridge Rindge and Latin School—a public school, but one where the Catholic ethos of New England still lingered in the air. For a bright, introspective child, Catholicism offered a compelling drama: fall, redemption, sacrifice, and resurrection.

In a revealing 2015 interview with The New York Times , the journalist asked him directly: “Are you an atheist?”