It might have been impossible to convert "Agnes of God" from a play into a movie under any circumstances, since the intrinsic reality of film throws the play's conceits and contrivances into sharp relief. Speeches that seemed stylishly theatrical on stage seem, in screen close ups, to be. . . merely theatrical. But that's just the beginning of this film's problems. It considers, or pretends to consider, some of the most basic questions of human morality and treats them on the level of "Nancy Drew and the Secret of the Old Convent."