Os Guinness talks about differences between Christianity and other religions in an interview with Justin Brierley a few years ago. He made a statement that Christianity is the only “traveling religion”.
He observed that Hinduism began in India and remains primarily in India. Buddhism began in India and remains primarily in India and Eastern Asia. Islam began in the Middle East and remains primarily in the Middle East. Christianity, however, began in the Middle East. Then it moved to Europe; and then it moved to North America; and now Christianity is growing fastest in Africa and Latin America and Asia.
While I think Guinness overstates the case little bit, he got me thinking about the how the major world religions have spread. For instance, Islam, which rivals Christianity in numbers, grew very rapidly during the life and immediately after the death of Muhammad. It spread throughout the centuries into Europe and down into Africa and more recently across Southern Asia.
To that extent, Islam rivals Christianity in its “travel” around the world. But the spread of Islam looked different than the spread of Christianity. This is the significant fact, in my opinion – not so much that Christianity has traveled through all the world (though it has) like no other religion.
Comparison to the second largest religion by the numbers, Islam, illustrates the point. Early on, during Muhammad’s life, and thereafter, Islam was spread by the sword by which people were forced en masse to convert, conquering. Muslims conquered approximately one third (1/3) of the known world by the sword. People were forced to remain devout by the same threat.
Devotion to Islam by people born into Islam is still enforced by criminal and civil law today in the countries in which Islam has the most control. Many the Muslims who convert to Christianity face social rejection or imprisonment, and sometimes murder or execution.
“Until the late 19th century, the vast majority of Sunni and Shia jurists held that for adult men, apostasy from Islam was a crime as well as a sin, an act of treason punishable with the death penalty….” The majority of modern Islamic jurists continue to regard apostasy as a crime punishable by death. As of 2014, a survey of laws in Muslim-majority countries reveal criminal sentences ranging from execution, imprisonment to no punishment, and civil penalties including voiding rights of marriage and denial of child custody and inheritance rights.
The spread of Christianity historically has happened very differently. Christianity began under hostile circumstances. Jesus was crucified. Unlike the other messianic figures at that time, his followers did not disperse and go away. Rather, the following caught fire, and thousands of people were added within months after his death, prompted by the claim that Jesus rose from the dead and appeared to hundreds of them.
In the 1st generation and century to follow, persecution drove the early Christians out of the area in which Christianity was born. People were scattered by persecution far and wide, into Africa, up into Asia Minor and Southern Europe, over into the western area of Asia and further east into India. Rather than spreading by the sword, the sword (in effect) scattered Christians who were largely the victims.
Christianity spread and flourished despite the early opposition and persecution. Early Christians had no political, cultural, social or military power or influence. Yet Christianity spread rapidly at a grass roots level.
Christianity took hold in Rome and continued to thrive in Rome for centuries despite some of the worst persecution in history. Nero ordered Christians to be set on fire at night to light up the boulevards in Rome. Christians were used for sport in coliseums, put to death at the hands of weapon-wielding gladiators and hungry animals for the amusement of the people.
Christianity continued to spread under similar hostile circumstances around the world, and that phenomenon continues today. In fact, it almost seems as if Christianity prospers and flourishes most in hostile environments.
Among the fastest growing churches in all the world is the church in China. The Council on Foreign Relations calls it “a religious revival over the past four decades” with an average of ten percent (10%) growth annually since 1979. Os Guinness stated (without citing a source) that 12,000 people a day were converting to Christianity in China as of 10 years ago. News outlets not many years ago were predicting that China would have more churchgoers that the United States as soon as 2030. (See for example, China on course to become ‘world’s most Christian nation’ within 15 years)
Of course, China is currently cracking down on Christianity (and religion generally). We will see how that growth continues, but the point is that Christianity tends to grow in hostile environments. Until very recently, China was opening up, but it didn’t encourage religion. Perhaps, the recent growth has led to the clamp down on religion.
Despite “intense persecution” in Iran, “Iranian Christians are witnessing one of the ‘fastest growing underground church movements’ in the world’”. “Open Doors USA, which says that Christians in Iran suffer extreme levels of persecution due to Islamic oppression, estimates that there are nearly 800,000 Christians in the country, still a small minority of the 80 million-strong population.”
I have heard Nabeel Qureshi, a convert from Islam who became Christian apologist, say that more Muslims have converted to Christianity in the first 20 years of the 21st century than all the past centuries combined. David Garrison calls it “the greatest turning of Muslims to Christ in history”. This phenomenon is happening in those Muslim majority countries where conversion means ostracism from family, punishment and maybe even death.
In Syria, former Muslims are turning to Christianity following the ISIS insurgence. One interviewee who wished to remain anonymous said, “’Most of the brothers here converted or come to church as a result of what ISIS did to them and to their families,’ he added. ‘No one is forced to convert. Our weapon is the prayer, the spreading of spirit of love, brotherhood and tolerance.’”
No one is forced to convert. No one is forced to remain a Christian. While there may have been some dark times in the Church in which people were persecuted (mainly by other Christians) for what were deemed to be heretical views, Christianity has not spread by force or threat or force. Christianity spreads as individuals hear the message, read the Bible and believe.
Thus, while I think Os Guinness overstates the proposition that Christianity is the only “traveling religion” in the world, I think there is a point of difference between Christianity and all other religions, nevertheless. Christianity has historically thrived in the most hostile circumstances. Christianity spreads not by the sword, and not by family heritage, but by individual conversion, by God working in the hearts of individuals, some of whom take great risks to declare their allegiance to Christ. This is a difference worth noting.
 See Nabeel Qureshi// Why I stopped believing Islam is a religion of peace, interview with Justin Brierley on Christian Premiere Radio, June 27, 2016.
 See for instance, When Muslims Become Christians; Ex-Muslims: They left Islam and now tour the US to talk about it; and Apostasy in Islam on Wikipedia.
 Apostacy in Islam citing Lewis, Bernard (1995). The Middle East, a Brief History of the Last 2000 Years. Touchstone Books. p. 229. ISBN 978-0684807126. Retrieved 27 November 2015.
 Apostasy In Islam citing Omar, Abdul Rashied (16 February 2009). “The Right to religious conversion: Between apostasy and proselytization”. In Mohammed Abu-Nimer; David Augsburger (eds.). Peace-Building by, between, and beyond Muslims and Evangelical Christians. Lexington Books. pp. 179–94. ISBN 978-0-7391-3523-5. Archived from the original on 11 January 2016.
 See Apostasy citing Laws Criminalizing Apostasy Archived 11 October 2017 at the Wayback Machine Library of Congress (2014); Apostasy Archived 4 September 2014 at the Wayback Machine Oxford Islamic Studies Online, Oxford University Press (2012); and Zwemer, Samuel M. “The Law of Apostasy”. The Muslim World. 14 (4): 41–43, Chapter 2. ISSN 0027-4909.
 Iran Is Witnessing ‘One of Fastest Growing Church Movements,’ but Christians Face Intense Persecution, by Stoyan Zaimov, Christian Post, October 16, 2018.
 See A Wind In The House Of Islam: How God Is Drawing Muslims Around The World To Faith In Jesus Christ Paperback – January 1, 2014