At least one in ten Protestant church-goers in the United States attend weekly services at "megachurches" of thousands, even tens of thousands, of worshipers. Over the past decade, this phenomenon has spread worldwide, with at least one megachurch in South Korea boasting almost 100,000 members. Why are megachurches so popular? How did they originate, and what factors have fueled their rise to such incredible prominence within Christianity, the largest religion in the world? How does the popularity of megachurches relate to the increasing numbers of people who identify their religion as "none," yet attest to attending a church at least weekly? This lecture will aim to answer these questions, while examining this remarkable development in Protestant Christianity.