Based on extensive data from 2010, Islam and Hinduism are the religions whose populations are mostly likely to expand in the future, while Jews and Zoroastrians, who have low birthrates and do not actively encourage converts, have the poorest growth prospects.
Jews, at 14 million, are only 0.2 percent of the world population, and have the highest median age at 36. Zoroastrians are an even smaller percentage of the world’s population, although 2,000 years ago they outnumbered Jews by more than two to one. Both religions have low birth rates and even lower rates of conversion.
In countries like the United States proselytizing or outreach is an important aspect of a community’s growth. In an open society every religion will suffer some defections. Unless a religion can attract an equal number of outsiders its population will decline. About 1 in 6 (16%) of American adults have changed their religious identification during their lifetime. Baptists gained the largest number of any religion; 4.4 million. But they also lost 4.6 million. Roman Catholics lost the greatest number of members; 9.5 million. However, they also gained 4.3 million converts who offset almost half of their losses.
According to the new study entitled “The Global Religious Landscape” issued by the Pew Forum on Religion and Public Life on 12/18/12, Christianity’s median age is 30 and Hinduism’s is 26. Muslims had the lowest median age at 23 years, compared to 28 for the whole world population and 36 for Jews. Pew Forum demographer Conrad Hackett, compiler of the 2,500 censuses, surveys and population registers used to make the report said, “Muslims are going to grow as a share of the world’s population and an important part of that is this young age structure,” Hackett said.
The two largest religions in the world are the two who proselytize with the most energy: Christianity and Islam. Christianity is the largest religion at 2.2 billion adherents or 31.5 percent of the world’s population. The Roman Catholic Church makes up half of that total, with Protestants and non-denominational churches at 37 percent and Orthodox at 12 percent. There are about 1.6 billion Muslims around the world, or 23 percent of the global population. The overwhelming majority (87-90 percent) are Sunnis, about 10-13 percent are Shia Muslims.
The world’s Hindu population is concentrated mostly in India, Nepal and Bangladesh. Half of the world’s Buddhists live in China, followed far behind by Thailand at 13.2 percent and Japan with 9.4 percent. Christians have recently replaced Buddhists as the majority in South Korea.
The study said that 97 percent of the world’s Hindus, 87 percent of its Christians, 73 percent of its Muslims and 41 percent of the world’s Jews lived in countries where they are a large to overwhelming majority. Christians make up the majority in 157 countries and Muslims in 49, including 19 of the 20 states in the Middle East and North Africa. By contrast, Hindus are in the majority only in India, Nepal and Mauritius; and Jews are a majority only in Israel.
Rabbi Alan S. Maller’s web site is rabbimaller.com