For 20 years, David Barrett's "Annual Statistical Table on Global Mission" (available in the quarterly International Bulletin of Missionary Research) has offered a numerical cornucopia to anyone interested in pondering the state of Christianity, and indeed of religious belief, throughout the world. Even for the statistically-challenged (like me), two large conclusions jump out from Dr. Barrett's 2005 table.

The first is the good news: As a global phenomenon, Christianity is by no means withering away under the assault of modernization; the only exception is Europe, where Christian decline is the rule. The not-so-good news, from the point of view of Matthew 28: 19 and the "Great Commission" ("Go therefore and make disciples of all nations..."), is that Christianity's impressive absolute growth in the last century is not matched by its relative growth: Christianity claims a slightly smaller percentage of world population today than it did in 1900.

Of the 6.4 billion people on Planet Earth, some 2.1 billion, or 33.1 percent, are Christians of one sort or another. As there were only some 558 million Christians in the world in 1900, the absolute growth of Christianity is, as I say, impressive. But because world population has grown at a somewhat faster pace than Christianity, Christianity's relative position has slipped a bit since 1900, when Christians represented some 34.5 percent of world population.

David Barrett divides the Christian world into what he calls "ecclesiastical megablocs." Of the world's 2.1 billion Christians, 1.1 billion are Catholics, 375 million are Protestants, 219 million are Orthodox, and 79 million are Anglicans. 34 million are "marginal Christians" (who believe in a revelation in addition to the Bible or who have off-brand views on Christ or the Trinity --- Jehovah's Witnesses, Swedenborgians, Theosophists, Mormons, etc.).

The remaining 426 million --- the second largest "megabloc" --- are "Independents," which Barrett defines as those Christians "separated from, uninterested in, and independent of historic denominational Christianity" (think of the explosive growth of house churches and new micro-denominations in Africa and Latin America). Fifty-nine percent of the world's Christians live in cities, a dramatic change from 29 percent in 1900.

Europe, including Russia, still claims the largest absolute number of Christians (531 million); but Europe is also the only continent where Christian numbers are declining now and will likely decline for the foreseeable future. Latin America claims the second largest number of Christians (511 million), while Africa (2.36 percent growth per year) and Asia (2.64 percent growth per year) are the fastest growing parts of the Christian world.

Indeed, Christian growth in Africa is nothing short of astonishing. There were 8.7 million African Christians in 1900; there are 389 million African Christians today; and Barrett projects almost 600 million African Christians by 2025 (when Europe's Christian population will have fallen to 513 million).

Many of the numbers, then, are encouraging: 54.3 percent of the world's population was unevangelized in 1900, compared to 27.9 percent today. Yet for all that growth, the implementation of the "Great Commission" seems to have stalled. By 2025, world population will be 7.8 billion, with a total Christian population of 2.6 billion --- a very, very modest relative growth of 0.05 percent over the next quarter-century.

Meanwhile, the world Islamic population is expected to climb from 1.3 billion to 1.8 billion --- almost certainly because of higher birthrates rather than conversions, but the fact remains that Christianity is growing at a decidedly slower pace than the other great world religions with global, culture-forming claims and ambitions. What would happen, though, if China opens itself to Christian mission in the next quarter-century?

In addition to these big picture numbers and trends, the Barrett "Status of Global Mission 2005" report is chock-full of interesting detail. Did you know that giving to Christian causes will reach $340 billion this year? Or that 440 million computers are in "Christian use"? Or that 68.4 million Bibles will be distributed in 2005 (up from 25 million in 1970)? Or that you are reading one of the world's 43,000 Christian periodicals? Or that there are 2.3 billion monthly listeners to Christian broadcasting?

All of which amounts to a very complex story, replete with promise but also with danger.

George Weigel is a senior fellow of the Ethics and Public Policy Center in Washington, D.C.