I just finished The Next Christendom by Philip Jenkins, and will admit to being pleasantly surprised by the book's depth and the author's breadth of knowledge. The article in The Atlantic Monthly last month was a poor (if somewhat accurate) distillation of the nuance and subtly of his ideas.
Jenkins' ideas aren't revolutionary. Scholars have been predicting (warning?) of the browning of Christendom for years. The Pentecostal religious movement has injected pluralist competition into the previously stagnant religious marketplace of Latin America while Africa is a God(s) intoxicated continent. The numbers Jenkins presents are pretty undeniable in the generalities: while European and to a lesser extent North American Christianity will desiccate due to secularism, Africa, Latin America and Asia will bloom as the centers of Catholicism and Protestantism.
The author notes clearly that the coming transnational Christendom is a recapitulation of the faith's ancient roots. Jenkins makes a good case that there were more Christians outside Europe than within during the High Middle Ages . In the Dar-al-Islam of the age of the Crusades that raged in the Levant and Spain it is likely that Christians were about half the total population in the Muslim Middle East! Even into the 19th century Christians formed as much as 20% of the population of Arab Muslim lands (and were the majority along portions of the Syrian coast and the highlands around Mt. Lebanon). He points out the antiquity of Christianity both in Armenia and Ethiopia, as well as giving much ink to the Nestorian Diaspora that was swallowed by the expansion of Dar-al-Islam .
So Christianity is returning to its roots, no? Yes and no. The initial expansion of Christianity was more like the slow baking of a cake, the current growth of the faith is more like flash frying. Let me elaborate. Christianity waxed and matured in the eastern Mediterranean between 30 and 300 of the common era. Even around 400 the faith was weak in the Western Empire, and in the middle of the 5th century the regent of the Emperor was a follower of the old religion. Eventually though, paganism died in the Mediterranean. The philosophers were expelled from Athens by Justinian early in the 6th century, and the rustic pagans were of little consequence. Around 600 St. Gregory the Great initiated the great missionary endeavors that eventually brought northern Europe into the fold. Christianity reached its peak in the eastern Mediterranean at this time (the queen of Persia, Shirin, was a Christian as well) and solidified its position in the western portion of the Roman Sea. Ireland was Christian and coaxing Scotland toward that path and the Anglo-Saxons of England were finally beginning to convert. The Franks held the line at the Rhine. Between 600 and 800 the peoples of continental Western Europe (the Dutch and west and south German tribes) were converted to the faith by Irish and Anglo-Saxon missionaries (who in their turn had been converted by Welsh and Italian missionaries). Between 800 and 1000 the Poles, Bohemians, Saxons (the mainlanders), Danes, Bulgarians, Russians and south Slavs joined the faith. Between 1000 and 1400 the last peoples of the Baltic and Scandinavia were baptized. The Christianization of Europe took 1,400 years, in starts and stops. Simultaneously Christianity lost first its political power, and later its demographic vitality, throughout the Dar-al-Islam. By 1500, Christianity was a European religion.
And Europeans have critically shaped Christianity. The Coptic Church of Egypt and the Jacobite Church of Syria have had little impact outside of their local regions . It was the Greek philosophers and Roman administrators that made the worldwide church what it is today. Concepts such as the Trinity owe much to the Greeks while Roman law and politics pervaded the body of the church. The book The Germanization of Early Medieval Christianity makes the case for the Germanic impact on the faith, but remember that the first German people converted were the Goths early in the 4th century, the last were the Swedish tribes around 1100. Christianity's putative Germanization was a gentle and subtle affair.
Now let us look to Africa. Jenkins notes that in 1900 fewer than one in ten Africans were Christian. Today half are, and the number is rising. He makes a believable case for the vitality of African faith. It lives and breathes in a way that the sterile steeples of the North can not match. These are people who feel the message of Christ deep in their bones, for they live in the times of the cruel Pontius Pilate, the hypocrisy of the Pharisees and the arrogance of the Saducees. Jenkins makes no apologies for Africa's grinding poverty and abject squalor. And he argues that this is the very source of its religious vigor because faith knows no bounds when faced with the crushing deprivation of life that parallels that of the ancient Christians.
African Christianity for Jenkins resembles the Primitive Church, before its assimilation by the temporal powers to be initiated by Constantine. Its emphasis on faith healing and ecstatic worship, the allusions to the End Times and rather high rates of sectarianism all highlight its similarities to the chaotic but vital early church. It seems to me that in fact it has little resemblance to the more controlled march of Christianity through pagan Europe. Europe was won by the Universal Catholic Church. Africa is being converted by thousands of sects. Christianization in Europe was the work of generations, in Africa that of decades.
This leads to one critique I have of Jenkins' book: he consistently argues that indigenous practices absorbed into the faith are as old as the faith itself. True, but the change was gradual before. The traditional European model was for a conversion of the aristocracy. Christianity would penetrate to the masses slowly and over many generations. It was the Reformation and the Counter-Reformation that finally resulted in the extirpation of pagan practices from much of Europe, hundreds of years after its final Christianization. On the other hand, Africans might be born pagan, convert to Catholicism, and then convert to Pentecostalism. The slow ebbing of practices from generation to generation is not analogous to this sort of change within one's lifetime. One can not look to history to predict the future, because historical parallels are few and far between for a massive continent-wide religious shift on this scale. It is as if centuries of cultural evolution are being compressed into a revolutionary life.
As to whether African Christianity is Christianity, the author makes a good case that it is. But he also makes it clear that it is a different sort of religion, more like the Christianity practiced in Europe in 300 rather than 2000. While we in the West might find the rantings and ravings of Falwell and Robertson rather peculiar, they pale in comparison to the charismatic preaching of African God-Men and prophets. African Catholic bishops have revived exorcism and faith healing, and some clerics have mooted the idea of animal sacrifice. The rather higher levels of sexual activity by African priests as reported by The National Catholic Reporter also makes us wonder what kind of Christianity is developing in the Third World. Jenkins is skeptical of the stories of rape and sexual abuse, and clearly wants to give the benefit of the doubt to the African clergy. Though his tone is generally objective, I do feel he sympathizes greatly with Southern Christianity, and feels that it is more authentic than Northern Christianity. Certainly, he is correct if he means that Southerners believe in an active personal God, while Northerners do not (I speak in generalities, but even the most traditional of Northern Christians pale next to the literal faith of Southerners according to this book).
I have focused on Africa primarily because Jenkins has. He gives much space to Latin America, and to a lesser extent Asia. But these two regions are different, because Latin America is nominally Christian. Asia on the other hand is predominantly non-Christian, and seems likely to remain so in the foreseeable future. Jenkins is more sober in his assessment of Asian Christianity than most American observers. Many commentators speak of the coming Christian China, but while Jenkins assumes Christianity will grow robustly, he does not foresee that it will become China's majority faith in the near future. I believe that those who overestimate Christianity's impact on China are blinded by one factor, their own Christian faith. Many are fervent Christians who wish the Chinese would accept the Gospel (and laudably sound the alarm for persecution on a scale unheard of since Imperial Rome), while others are Chinese dissidents, a disproportionate (the majority?) of whom are Christian. South Korea, the most Christian country of East Asia, and similar in many ways to China (a small 1/20 scale model?) is 25% Christian . Japan is 1-2% Christian, while Taiwan and Hong Kong are 5-10% Christian and Singapore is 15% Christian . Christians have room for growth and maturation in these nations, and are overrepresented in the elites, but the percentages above indicate that the situation is different in kind from that of Africa, where only Muslims stand in the way of a mono-religious landscape on the order of Latin America or the Middle East.
In India, the census records that Christians form 2-3% of the population. This is likely an underestimate, as Christian and Muslim Dalits do not receive government benefits (while Hindu and Buddhist ones do), and so will often not report their true religious affiliation. The cancer that is caste in Hindu India certainly gives an opportunity for Christians, but Dalits and Tribals together form no more than 25% of India's population, so I suspect that a Christian India is very far off in the future (if at all). Jenkins points out that Christians in northern India are 90% Dalit while those of southern India are 60% Dalit. Those of Pakistan are almost all former Hindus of low caste. This concentration amongst the lower classes in India does not bode well for the future of the faith, as it stigmatizes it. Jenkins also notes that Pentecostal Christians derive from the lower classes in Latin America.
The author seems to believe that this spread of Christianity amongst the dispossessed is a repeat of the ancient pattern. I believe he is incorrect, and that most modern scholarship disproves Nietzsche's contention that Christianity was a slave religion. In fact, Christianity was the religion of the middle-class, the bourgeoisie, in the ancient world. The rustics and the political and intellectual elites were latecomers. Later Christianization of Europe occurred from the top-down, with the conversion of the ruling class. This bottom-up pattern that is occurring in India, and the Pentecostal growth in Latin America, contrasts with the historical precedent and also the mode in Africa and Asia . Christianity is the religion of the upwardly mobile middle-class in Asia and the urbanized elites in Africa. This makes Jenkins' attempts to forge the idea of a "Southern Christianity" less tenable and to me explains part of the reason he avoids detailed descriptions of Asian Christianity.
But the relative poverty of many converts makes the relevance of Southern Christianity open to doubt. Pentecostals form 25% of Chile's population, but the elite is firmly Catholic, as is the middle-class. Similarly, Protestants are concentrated among the Maya in Mexico. Guatemala has had a Protestant President, but they may form 40% of that country's population, so demography does overrule socio-economic status in this case (they are mostly Maya but the military is pro-Protestant because of issues with Catholic Liberation Theology). Jenkins talks much about the growth of African Christianity, which is true, and most thorough among the elites. But we all know the continent is a basket-case . Does anyone expect Northerners (or Asians or even Latin Americans) to take the spiritual lead from a region so devoid of political order and economic dynamism (the eastern provinces of late Imperial Rome were economically more advanced and secure, and more Christian)? In the United States, the Southern Baptists are the largest Protestant denomination. But many more Presidents have been Episcopalian than Baptist. Class matters. As one climbs the social ladder, religious affiliation changes. The hostility toward John Ashcroft is much more about class and culture than religion, for he is a member of the Pentecostal Assemblies of God. Their religious beliefs are frankly no more kooky than any other Christian sect, but they actually take their magical faith seriously! Jenkins asserts that the United States is a nation of Indians ruled by Swedes (in terms of religiosity). I see no reason why he can't make the jump toward a world of Swedes ruling Indians.
Social capital matters as much as demography. If it is one Christian group that will rise to the fore in the next century, it will be Asians. Though somewhat smaller numerically than Africans, the large population of Asia means that they will be in the same order of magnitude. Traditionally, the Chinese have been Buddhist, Confucian and Taoist. I think they may have to add Christian to make it a quartet. Japanese Christians have always had influence above and beyond their numbers, it is an open secret that many female members of the royal family in Japan in the first half of the 20th century were Christian. The Philippines may finally join the "A-list" of Tigers while the Christian Chinese of Indonesia will almost certainly spearhead that nation's economic rise if it so occurs.
In addition, Europe will be even more thoroughly de-Christianized. Jenkins makes the case that Christian immigration will halt and possibly reverse this, but it is weak. He notes that half the practicing Christians in London are black, and that Christianity and blackness are becoming closely associated in that region (hampering outreach to the majority white community). But he does not deny the rise of Islam. North Africa, Turkey and South Asia are the primary sources of European immigration, and they are all strongly Muslim in flavor (the Hindu segment among South Asians is not inconsequential, but not proportionate to their numbers in South Asia). The African Christian presence is smaller and less assertive. The European elites, and even the commoners, are settling into an apathetic theism that borders on agnosticism. With the European Union rising to become the New Babylon, one can be safe in saying that Secularism is not a spent force. Mind is as important as matter, and though their numbers are low, Europeans are a technologically sophisticated people who will do fine without the grace of God.
Speaking of intellect, the Greeks showed that theology matters. What theological insights will the African Christians and Latin American Protestants offer ? There are more Latino Protestant seminarians than Catholic ones in the United States in large part because the former have lower standards. This is a clue as to the relative low state of intellectual ferment of the South, as opposed to religious fervor and ritualistic innovation. Smells and bells does not a religious revolution make, and the foundational base of Southern Christianity owes much to the North, and I don't see that changing. As Southerners modernize, Jenkins admits that they may abandon many of their magical God-intoxicated ways. He notes that Africans often shift to more traditional denominations with increased literacy and education. In the end, after foretelling the tale of a religious century that will resemble the 3rd more than the 21st, Jenkins seems to backtrack and offer that the model of secularization might not be totally bankrupt.
Finally, let me end on a personal note. Southern Christianity terrifies me. Its juju and fervor are alien to my every bone and being. The tame and well-behaved Presbyterianism of Scotland and stuffy Catholicism of Ireland I can abide, I can understand, and I can dispute. What would I have to say to someone who wishes to perform a faith-healing on me? Someone twitching from the power of the Holy Ghost? A century of religious wars, a century of Enlightenment, a century of Muscular Christianity and a century of unspeakable barbarity have brought us to the age of Secular Humanism in the West. The Christian Fundamentalists know the truth and call a spade a spade. Christopher Reeve (a born-again Unitarian-Universalist) recently stated that "...I began to answer by saying that I'm not sure if there is a God, but I try to behave as if He is watching...." Well Mr. Reeve, perhaps, but I have long felt that many "Christians" live lives as far removed from the faith of the Church Fathers and the generations after Christ, one predicated on a living breathing God that works miracles and condemns those outside his saving grace, as I myself do, one totally bereft of religious feeling from birth, and likely to my death. Yes, they go to church and take communion and utter the public pieties necessary to fulfill social convention and expectation, but in the West God has died, and I thank Him everyday that He has. In Southern Christianity I see His rise, and I fear it a great deal. If that doesn't convince my fellow secularists of the need for an immigration pause, I don't know what will.
 He loads the die though-he notes that Lithuania was pagan until 1387, and that it was Europe's largest state at that point. Very true, but though Lithuania was not a Christian state, it was a state of Christians. By this, I mean that though the military aristocracy that ruled it were pagans of Lithuanian Baltic extraction, most of the subjects under their dominion were Christians of Orthodox and Catholic professions. Lithuania was religiously tolerant, and the ruling family intermarried and prayed with the Catholic and Orthodox aristocracies of of the west and east Slavs respectively, before their final turn west toward the Catholicism of the Poles. In any case, this case just illustrates that I think Jenkins overplays his hand in specific cases to make his general overarching theme-the diminution of the importance of Europe in Christendom's history, past and future-more airtight.
 Quibble here, but Armenia's Christianization prior to Constantine's Edict of Milan has been disputed. Jenkins accepts uncritically the date of 300 for Armenia's Christianization, but I have read works that indicate the king of Armenia simply rewrote the histories after he became Christian to curry favor with the newly baptized Roman Empire. Prior to his Christianization Tiridates III was in fact likely a persecutor of Christianity ... to curry favor with the Emperor of Rome, the fanatic traditionalist Diocletian.
 Syrians were crucial in spreading the faith east and south, to Persia, India, Central Asia and Ethiopia. But only Ethiopia remained Christian, and for most of history it has been a hermit kingdom.
 Also the Orthodox Church, but remember that final schism did not occur until 1054, by which time most of Europe was already Christian.
 The torrid growth of the South Korean churches seems to have ceased in the 1990s. While Seoul is a Christian city, Pusan is a Buddhist one. And 50% of South Koreans still don't give a religious affiliation.
 Singapore is mostly Chinese, so I add it to the list of East Asian nations on ethnic grounds.
 Latin American Catholicism is often very nominal amongst the lower classes, and it seems likely that in Catholic nations such as Chile or Brazil, that most practicing Christians are Pentecostals, not Catholic!
 Jenkins predicts that religious conflict between Christians and Muslims in Africa will become endemic, while tension between Protestants and Catholics will flare into violence. Southern Christianity will bleed itself into the Enlightenment perhaps, just as Northern Christianity did centuries ago.
 On the other hand, the Koreans, a scholarly people, do seem to be getting together and hashing out serious issues.