High fertility plus conversion, not doctrine, make world religions

Evidence

To survive and prosper, religious groups attract followers, induce adherents to reproduce at rates greater than replacement levels, or, as the demographic expansion of the Mormon Church shows, ideally, do both. The importance of demographic processes in the cultural survival of groups cannot be overstated. The Mormon Church grew, in a time span of just 170 years, from a small group of a few hundred to 15 million followers worldwide. Likewise, Christianity itself grew by leaps and bounds in the Roman Empire, and a once obscure offshoot of Judaism became the state religion of the empire in less than 300 years. A similar story can be told about the rise and spread of Islam. It is these dramatic demographic expansions that make a religion a world religion. — Norenzayan, Ara, Big gods - how religion transformed…, 491

Categorization

• DEFINE: Sharpens what ‘world religion’ means demographically: expansion through reproduction and conversion, not theological content.