Raised a Christian, Manuel Gomez now goes by Mohamed Chechev, and counts himself among a handful of Tzotzil Indians converted to Islam by Spaniards in southern Mexico. "I am Muslim. I know the truth. I pray five times a day, celebrate Ramadan and have travelled to Makkah," Chechev said in rudimentary Spanish. He lives in a mainly Protestant community in Chiapas called Nueva Esperanza on the outskirts of San Cristobal de las Casas, where he shares a modest house with 19 relatives and sells vegetables he grows on a plot of land. Biblical references abound in Nueva Esperanza, with streets...