Oh, and by the way, if you say your father is a Christian, that’s using the word as a noun, not an adjective. I’ve got no problem with that. It’s the use of the word as an adjective that I’m making a case against. If you say “I have a Christian father,” I might be at a loss. Roman Catholic? Evangelical? Methodist?
And my larger case is that language can determine how carefully one thinks about things, and this business about the word “Christianity” is an example.