This quotation from Richard III may be more than just incidental—it certainly seems so—but I'm not familiar enough with the film to dig deeply into its significance.
But I can point out the connections between religion and theatre that the scene evokes. The film is about a theatre director who is hired to put on scenes from Christ's passion for a church pilgrimage of sorts. The unorthodox theology behind his presentation makes a number of people nervous and angry.
In the scene below, a character contemplates his own history. He presents theatre and religion as something of a dichotomy. He loved the theatre, but he felt that he had to pursue religion instead:
The rest of the film may, in part, be contemplating whether religion and theatre are irreconcilable entities. Perhaps it is even taking us back to the origins of the theatre in English—to the medieval mystery plays themselves.
Links: The Film at IMDB.