Early this summer, Paul Crouch of the Trinity Broadcasting Network (TBN) wrote to supporters, telling them that the network's spring "Praise-a-Thon" was a success. For five days, Crouch and a slate of other televangelists had raised money on-air for TBN, the largest Christian television network in the world. "TBN is debt free," Crouch wrote. "Free to invest every penny into expansion to the rest of the world!" For TBN, that means investing in broadcasting its Christian-themed programs on thousands of cable systems and more than 5,000 television stations. But it also means investing in something else: Southern California real estate....