Mere Christianity has been referred to as a classic of Lewis's career,[23][24] as well as of religious literature,[25] particularly in the category of Christian apologetics.[26] Commentators have also seen it as a guide to the basics of the Christian faith[27] and to his theology.[28] The book, along with his arguments for the existence of God, have frequently received academic evaluation,[29][30] either complimenting or critical.[31] Analysing Lewis's books, the Australian archeologist Warwick Ball believed Mere Christianity is perhaps his most influential and widely read apologetic work;[32] the American philosopher C. Stephen Evans called his moral argument the "most widely-convincing apologetic argument of the twentieth century";[33] McGrath considered it "perhaps as outstanding an example of a lucid and intelligent presentation of the rational and moral case for Christian belief as we are ever likely to see".[34]
Mere Christianity has retained popularity years after its publication,[35][36] and has been compared to other well-known Christian works, including Augustine's The City of God and G. K. Chesterton's The Everlasting Man (1925).[37] The BBC journalist Justin Phillips observed that it "continues to transform the lives of those who read it. There is no reason why it won't continue to be potent for decades to come."[38] According to the authors Roger Lancelyn Green and Walter Hooper, its success led to the acknowledgment of Lewis as "one of the most 'original' exponents of the Christian faith" of the 20th century.[39] The book, Hooper continued, shows Lewis's ability of providing a comprehensible guidance of the Christian beliefs/theology to everyone,[40] and "has become synonymous with Lewis".[41] The academic Bruce L. Edwards noted that it contributes to shaping Lewis's reputation as "a witty, articulate proponent of Christianity".[42] The author Marvin D. Hinten wrote: "When people are asked which C. S. Lewis book has most influenced them spiritually, the most common answer is Mere Christianity."[43]
According to Peters, the book is more popular among Christians of various denominations,[44] including Catholic, Latter-day Saint, Orthodox, and Protestant,[45] but less among non-Christians.[44] It is often used as an evangelistic tool,[46] predominantly in Christian-majority countries, including the United States, where its influence is most felt.[47] Furthermore, its influence is strengthened by the publication of its translations;[48] according to Marsden, it has been translated to about thirty-six languages.[49] In the next decades, Mere Christianity is continued to be reprinted and sold by Christian[50] and online booksellers.[51] For instance, soon after the dissolution of the Soviet Union, it was translated into the several native languages of its breakaway states, which was done by Orthodox Christians to rebuild their influence.[49] As of 2010, the book had been in BookScan Religion Bestseller's list for 513 weeks, consecutively.[52] There is also a considerable readership in China, with 60,000 copies had been sold there as of 2014.[49]
The book has also been cited by a number of public figures as their influence to their conversion, or re-conversion, to Christianity as well as other Christian denominations.[53] The American geneticist Francis Collins related his story of conversion from atheism in his book, The Language of God (2006),[54] and described Mere Christianity as having influenced him to embrace Christianity.[55][56] The American attorney Charles Colson's conversion happened after him reading a copy of the book given by his friend, Thomas L. Phillips (the chairman of the board of the Raytheon Company).[57] His story became popular, enhanced by the release of his autobiography in 1976, which was consequently declared the "Year of the Evangelicals" by the Newsweek magazine.[58] Catholic converts include the British philanthropist Leonard Cheshire, the German economist E. F. Schumacher, the American author Sheldon Vanauken, the American columnist Ross Douthat, the American theologian Peter Kreeft, and the American philosopher Francis J. Beckwith.[59]
Mere Christianity has been featured in several lists.[60] It was included in the 2000 book, 100 Christian Books That Changed the Century, by William J. Petersen and Randy Petersen.[61] In 2000 and 2006, the evangelical magazine Christianity Today's editorial board included Mere Christianity in its "Books of the Century" and "The Top 50 Books That Have Shaped Evangelicals", respectively.[62][63] In a 2013 article to Christianity Today, McGrath ranked it the first among the five books by Lewis he liked the most.[36] In the same year's "The Best Christian Book of All Time Tournament", run by InterVarsity Christian Fellowship, Mere Christianity was voted as the all-time, best Christian book, only after Augustine's autobiography Confessions.[64] In 2018, Christianity Today's Greg Cootsona, a writer of the relationship between religion and science, featured it in his "5 Books That Bring Science and Christianity Together" listing.[55]
Mere Christianity has influenced other Christian publications,[65] with the scholar Gary L. Tandy noting that it remains the standard for assessing them, mainly the apologetic ones.[66] Subsequent publications with allusion to the book in their titles include N. T. Wright's Simply Christian (2006) and McGrath's Mere Apologetics (2012).[66][67] The American pastor Tim Keller referred to his apologetic The Reason for God (2012) as "Mere Christianity for dummies".[68] The bimonthly ecumenical Christian magazine Touchstone, which started publication in 1986, is subtitled A Journal of Mere Christianity.[69][70] Paul McCusker's C. S. Lewis & Mere Christianity, which provides insights to the work in its historical context, was published in 2014; it was praised for being well-researched but was criticised for its factual errors.[71] Another "biography" of the book, C. S. Lewis's Mere Christianity, written by Marsden, was released in 2016,[72] and received a positive reception from critics,[73][74] with some criticism to its conclusion.[75]
