What is the theme in Swimming Lessons by Rohinton Mistry?

Religion runs through many of the stories in this collection, but only rarely comes into focus. The first shows a husband, Rustomji, who considers religious customs meaningless but tolerates his young wife's intense piety. Setting the action on a Parsi feast day heightens the tension. Mehroo has always loved the fire temple and wishes her children cared about their religion. Since childhood, she has cherished the dustoor (priest) Dhunjisha, whom Rustomji insists is, beneath his priestly garb, a dirty old man, making lewd remarks between prayers, and is crushed the old priest is murdered and prayers canceled that day.