Filmmakers travel through Europe to uncover the little-known story of a painting said to be inspired by the mystical vision of Saint Faustina.
| Actor | Role |
|---|---|
 Jim GaffiganSelf | Self |
 Harry Connick Jr.Self | Self |
| CChristoph SchönbornSelf (as Cardinal Christoph Schönborn) | Self (as Cardinal Christoph Schönborn) |
 Bishop Robert E. BarronSelf (as Bishop Robert Barron) | Self (as Bishop Robert Barron) |
| SStanisław DziwiszSelf (as Cardinal Stanislaw Dziwisz) | Self (as Cardinal Stanislaw Dziwisz) |
| AArchbishop Gintaras GrusasSelf | Self |
| HHenryk CiereszkoSelf | Self |
| DDaniel DiSilvaSelf | Self |
| FFr. Michael GaitleySelf | Self |
| LLeo MaasburgSelf | Self |