November 2, 2011 — By Paul V.M. Flesher
The world's population has just reached seven billion through a centuries-long process of growth and migration. The same process formed the distribution of the world's religions as we now know them today. The current result of that process is somewhat surprising; more than half of the world's people follow one of just two religions: Christianity or Islam. These two monotheistic religions comprise the world's two largest religions.
Christianity and Islam both trace their origins back to the Jewish Patriarch Abraham. The biblical book of Genesis tells how, during the second millennium B.C., Abraham and his household of 80 people followed a god known as Yahweh. Abraham's family grew into the People of Israel who formed Judaism, the earliest monotheistic religion, and worshipped Yahweh only. Later, in the first millennium CE (Common Era, formerly A.D.), both Christianity and Islam drew upon Judaism to create new religions worshipping this same God.
Christianity migrated as it expanded. After it origins in the first century CE in Palestine, it became the religion of the Roman Empire. That established it in the lands around the Mediterranean Sea and then brought it into Europe. When the European nations began colonizing other continents in the mid-second millennium CE, they carried their religion with them, with the result that the population of three continents became almost entirely Christian: North America, South America and Australia. Christianity has also become the largest religion in the southern half of Africa.
After its origins near the coast of the Red Sea in the seventh century, Islam quickly moved into the Middle East and the northern half of Africa. From there it went east, colonizing the Indian sub-continent and moving further east into Malaysia and Indonesia, which today constitutes the most populous Muslim nation.
Today, Christianity comprises about a third of the world's population, around 2.3 billion. About a quarter of the world's population, roughly 1.8 billion, follow Islam.
If we look at a map of the world showing where members of these Abrahamic religions reside in comparison to those of eastern religions, the impact is even more striking. Christianity or Islam dominate every continent except Asia– -- and even there Russia and the Middle East belong to the Abrahamic side. About 13 percent of the world's land area is occupied by members of Eastern religions, while almost 87 percent is dominated by Christianity or Islam.
Of course, this land area view is somewhat misleading, because Asia is home to two of the world's most densely populated large countries, India and China. At more than 1.2 billion people each, these two countries contain more than a third of the world's population between them.
India is in fact home to the world's third largest religion, Hinduism, which counts about a billion adherents and roughly 14 percent of the world's population. Asia is home to most of the world's Buddhists, but guesses about their population are highly uncertain and range from 300-350 million.
This is where we reach the limits of our ability to count more precisely, however. Hinduism may be the third largest religion, but it is smaller than the number of people around the world who follow no religion at all. About 16 percent of the world's population does not attach to any religion. These range from committed atheists to agnostics and secularists to people who check "none of the above" on surveys of religious belonging.
We should not forget communism's work to stamp out religious belief in China, Russia and other countries, nor the rise of secular and scientific worldviews in Europe, the Americas and elsewhere. The ability to perform a more accurate count might lower each religion's population a few percentage points. But it would not in the end change the general picture.
Is this a triumph of monotheism? I would not characterize it as such because there is no unity. Islam and Christianity are highly suspicious of each other. Within each religion, large groups do not even recognize other groups as belonging under the same religious umbrella. Evangelical Christians do not recognize the Mormons as Christians even though they are called the Church of Jesus Christ of Latter Day Saints. Don't forget that Protestant Christianity was formed through the rejection of the validity of the Catholic Church. In Islam, there is ongoing Sunni questioning of Shiite and Sufi forms of the religion.
So rather than a single, large monotheistic religious umbrella, monotheism is simply a category that contains numerous, squabbling members. Indeed, the world's largest Christian nation, the United States, is also the home to the world's largest variety of Christianities, all of whom would rather remain separate than join together.
Note: Numbers in this essay are based on information found at Adherents.com and pewforum.org/Global-Muslim-Population.aspx. For a dynamic graphic illustrating the growth and movement of world religions, go to www.mapsofwar.com/ind/history-of-religion.html .
Members of the Abrahamic religions of Christianity and Islam together dominate more than 80 percent of the Earth's land area. ( Dbachmann, Wikimedia Commons)