Theater J is instituting something new, a festival called Locally Grown: Community Supported Art from Our Own Garden, designed to celebrate the D.C. area’s community of playwrights. The first play in the festival is Renee Calarco’s “The Religion Thing,” the story of two thirtysomething couples: Mo (Liz Mamana) and Brian (Chris Stezin) and Patti (Kimberly Gilbert) and Jeff (Will Gartshore). Mo and Patti have been friends for a long time. They’re both super-smart professional women. Their men are also savvy and attractive. At the beginning of the play, Patti introduces her new boyfriend, Jeff, to Mo and Brian.