Performing artist and writer Seth Lepore has channeled his doubts into “Losing My Religion: Confessions of a New Age Refugee,’’ a comic look at the strangeness and scams on the edge of American spirituality. The show plays the Arlington Center for the Arts Nov. 11 and 12. Alone onstage, Lepore alternates tales of his own journey with character sketches inspired by the deluded seekers and snake-oil salespeople he has met along the way.