Religious institutions have long offered their congregants services that go beyond worship. Particularly in the last two decades, they have begun expanding far beyond their traditional offerings to a wider and more diverse array of auxiliary uses - non-worship uses that are affiliated with a religious institution. (One type of large religious institution, the megachurch, is fast gaining members by offering schools, community centers, dining facilities, even movie theaters and gymnasiums.) Government has long granted special protections to the worship uses of religious institutions. A recent federal law - the Religious Land Use and Institutionalized Persons Act of 2000 (RLUIPA) - has nationalized how land use regulations apply to religious institutions. However, as this article argues, RLUIPA does not adequately address the problem of auxiliary uses. To avoid constitutional challenges to RLUIPA, Congress must rework RLUIPA to differentiate between those auxiliary uses that are substantially-related to a religious institution's mission and those that are not.