C. S. Lewis felt that we do not understand the post-Christian mind. One indicator is how most ministries try to reach post-Christian people.
Most of us associate Lewis with Oxford University. He did spend almost 30 years there, from 1925 to 1954, as a Fellow of Magdalen College. But in 1954, Lewis was awarded the newly founded chair of Mediaeval and Renaissance Literature at Cambridge University and was elected a fellow of Magdalene College. His inaugural lecture was adapted for a radio audience on November 29, 1954. It was titled “The Great Divide.”
The great divide is between Christians and post-Christians. Lewis saw history as falling into three ages—“the pre-Christian, the Christian, and what may be called the post-Christian.” Pre-Christians are pagans who have not heard. In a sense, they’re virgins, open to the gospel, so the divide between Christians and pre-Christians is small.
Not true with Christians and post-Christians. Lewis believed Christians err in assuming a post-Christian is also a pagan. “You might as well imagine a married woman recovers her virginity by divorce.” Translation: A post-Christian cannot revert to being a pre-Christian anymore than a married woman can revert to being a virgin. A post-Christian has moved on from the faith, divorced from it.
This means approaches that drew a pre-Christian to the faith will not prove effective with a post-Christian. They’re divorcees, turned off to the gospel. They’ve moved on. Their frame of reference for the faith is been there, done that.
For Lewis, the gap between a Christian and post-Christian can only be bridged by reframing the gospel, “producing new metaphors or revivifying old ones.” To revivify is to bring to life—to make fresh. That’s what I do. Clapham Institute is revivifying an old image for the gospel—a sphere—that served as a metaphor for God, the gospel, human sexuality, and renewal (i.e., innovation). It’s proving effective with post-Christians.
Lewis was way ahead of his time. In today’s religious landscape, the fastest growing percentage of the US population is exiles and religious “nones”—post-Christians. They’re mostly millennials. This past year, the millennial generation surpassed Baby Boomers in terms of numbers. It is the new “pig in the python.” The post-Christian world has arrived. We’re no longer in the 20th century.
For most of the 20th century, Christians sought to win people to the faith primarily by “front door” evangelism (preachers, evangelists, apologists). Post-Christians are as likely to listen to these speakers as a divorcee is likely to listen to someone describing the wonders of marriage. In most cases, the divide is just too wide.
The 21st century is post-Christian. Effective Christians will re-win people to the faith primarily by “side door” evangelism (participatory projects, learning labs, and so on). That’s what the original Clapham Sect did. They sought the “reformation of manners” (manners was another word for cultures). They worked with people of faith, no faith, and differing faiths. They facilitated collaborative projects, achieving over 60 cultural reforms over the course of four decades. They were way ahead of their time.
So was C. S. Lewis. He understood the times. So did the sons of Issachar—leaders who “understood the times, so they knew what Israel should do” (II Chronicles 12:32). Many of today’s ministries would be more effective if they understood we live in a post-Christian age. Like C. S. Lewis, they’d know what to do.
 C. S. Lewis, Selected Literary Essays, edited by Walter Hooper (New York: HarperOne, 1980), p. 265.