Hugh Grant once stated in an interview "I'm getting bored of playing obvious roles and being typecast" - writer/directors Scott Beck and Bryan Woods saw this interview and wrote the role of Mr. Reed with Hugh as their top choice for the role.
Sophie Thatcher and Chloe East were both raised Mormon so were able to give valuable insight into the religion when shooting the movie. They are no longer Mormons.
The end credits feature the statement: "No Generative Al was used in the making of this film."
While climbing/descending the stairs in the beginning, Sister Paxton brings up singing, and Sister Barnes mentions how she dislikes her own voice. Sophie Thatcher, the actress who plays Sister Barnes, performs a cover of "Knockin' on Heaven's Door" that plays during the credits.
None of the main characters are ever addressed by or receive a given name. They are simply known as Paxton, Barnes, Reed, and Kennedy.