The St. John Paul II Pastoral Center, a Roman Catholic mission, sits at the rough end of a former strip mall in the shadow of an Arby’s in Gainesville. The space, church leaders say, was once used as a nightclub and movie theater, a history now hidden by multiple coats of paint, pews brought in from other congregations, and a stone-and-wood shrine to Our Lady of Guadalupe, the patroness of the Americas especially revered by Mexicans. This mission, in the Archdiocese of Atlanta, was built in a hurry, to serve the many Latinos who labor at the poultry processing plants that form the economic backbone of Gainesville.