The phrase mere Christianity can be misleading, suggesting we can act independently of traditions that guide our interpretations of the Bible. It’s quite American to position ourselves above tradition, Sometimes even denominational churches do this by hiding their theological distinctives, thinking they will narrow the pool of potential parishioners. If you take Presbyterian out of the church name and avoid teaching about predestination and the sacraments, more people will come, right?
A friend of mine has a daughter-in-law who attends a large nondenominational church. My friend sent her the Heidelberg Catechism to introduce her to his Reformed theological tradition. Her response surprised him. She wrote back saying that her nondenominational church uses the Heidelberg Catechism all the time. It is one of her church’s key resources for educating people in the faith. Consider the irony: While many Reformed churches push their own catechism to the side, this large nondenominational church discovers the same catechism to be a profound tool for teaching the Christian faith. Still, both churches illustrate problems with mere Christianity.
One church claims to be nondenominational instead of naming its tradition. The other fails to uphold its explicitly named tradition.
C.S. Lewis had already clarified Billings’ main point, as seen in Lewis’ preface to his book Mere Christianity. Rather than putting forth “’mere’ Christianity as an alternative to the creeds of the existing communions,†he declared: “It is more like a hall out of which doors open into several rooms…. The hall is a place to wait in…, not a place to live in. For that purpose the worst of the rooms (whichever that may be) is, I think, preferable…. When you have reached your own room, be kind to those who have chosen different doors and to those who are still in the hall…. That is one of the rules common to the whole house.†[Lewis, MC, pp. xv-xvi of HC 2001 ed.]