After making allowances for countries that have, or recently have had, an officially imposed atheist ideology, in which there might be some social pressure to deny belief in God, one can venture conservative estimates of the number of unbelievers in the world today.
Reviewing a large number of studies among some fifty countries, Phil Zuckerman, a sociologist at Pitzer College, in Claremont, California, puts the figure at between five hundred million and seven hundred and fifty million. This excludes such highly populated places as Brazil, Iran, Indonesia, and Nigeria, for which information is lacking or patchy.
Even the low estimate of five hundred million would make unbelief the fourth-largest persuasion in the world, after Christianity, Islam, and Hinduism.
It is also by far the youngest, with no significant presence in the West before the eighteenth century.
Who can say what the landscape will look like once unbelief has enjoyed a past as long as Islam’s – let alone as long as Christianity’s? God is assuredly not on the side of the unbelievers, but history may yet be…