Much as I dislike disagreeing with C.S. Lewis, my personal nomenclature is to reserve the term Christian for those who live the values promoted by the Gospels. This is clearly non standard though, so I see the potential for confusion.
* https://en.wikipedia.org/wiki/John_20:23
* https://en.wikipedia.org/wiki/Sacrament_of_Penance
* https://en.wikipedia.org/wiki/Confession_(religion)
There was an early Christian heresy what believed that clergy must be faultless for their ministry to be effective and their prayers and sacraments to be valid:
* https://en.wikipedia.org/wiki/Donatism
And another belief that humans can be saved by their own efforts, without the need for God's grace:
* https://en.wikipedia.org/wiki/Pelagianism
In some ways your idea would be contrary to scripture (?): since no one can (fully/perfectly?) live those values, then no one can (fully/perfectly?) be Christian. Whereas is in the 'Lewis model' every one can be a Christian, but just a better or worse 'instantiation' of one.
Yeah, I definitely take that point.
That being said, I don't have a better term for the small number of people who actually try to live the teachings of the Gospels, as opposed to those who mumble along to the Nicene Creed, take the Eucharist and go right back to robbing their fellow humanity.
So that's the term I picked.
Like, to be fair, I am almost certainly a heretic from the perspective of the Catholic Church, but if the Source of All judges me based on that, then I guess we have very different priorities.
For context, I grew up in an Ireland where literally everyone was a practicing Catholic, but very few actually lived it in their lives, hence why this annoys me. As Jesus (did not) say, blessed be the hypocrites etc.