Can't speak for anyone else, but it is not unusual (nor new) for someone to describe themselves as "Catholic." Briefly, they usually mean that they are a member of the Roman Catholic Church. Wikipedia will provide a great deal of reading about it.

Neither is it unusual for someone to describe themselves as a particular Protestant denomination: Lutheran, Baptist, Methodist, Presbyterian, Episcopalian, et al. Again, Wikipedia is a good starting place.

People who simply describe themselves as "Christian" are what, in my experience at least, is relatively new. Going back, say, fifty years, it was somewhat unusual in many parts of the US to find people who described themselves that way.

In my experience, most of these people belong to one or another of what might be called non-denominational Christian churches. My preferred term for many of them is "contemporary American fundamentalist Christian," but that is not a widely used term, at least not that I know of.

Your question is strange enough that I'm honestly not sure whether or not you're trolling. If you are, as it seems you might be, a member of a contemporary American non-denominational Christian church, it is very weird, whether you know it or not, to suggest that a church that has existed for roughly two thousand years and has many more than a billion members wordwide is "splintering off" and "making [its] own religion."

Its more information in one word.

A lot of people assume "Christian" implies American evangelical values and beliefs (especially online), and many people want to make it clear they do not share those - e.g. biblical literalism.

Its common for people of many denominations to specify their denomination. People often say they are Anglican or Orthodox or whatever.

I will actually argue that it is very useful and wish that more people started to be more specific about their faith. Firstly, stating that one is Catholic/Lutheran/... demonstrates that one understand that one is not representing the entire Christianity. Secondly, it is useful for discussion as it makes one's dogmas/axioms more explicit. And thirdly, it allows better granularity as some general teachings are really Christian (like the resurrection and most of the Credo) while other are specific to the tradition one follows (like the sacraments).

For example, a Catholic would hesitate to receive a "Christian eucharist" as the Catholic and protestant understanding of the Eucharist is so profoundly different

A final point, given the subject of the thread, is that since the Catholic Church regards itself as founded by Christ, it is older than the Bible, and that the Bible was primarily written by the Church, for the Church, to complement Tradition. They would consider splintering off Tradition and leaving Catholicism as moving away from Christ (as Christ is head of the Catholic Church)

That's weird to me because most Catholic people I know (Chicago is a very Catholic city) would identify themselves as "Catholic", not as "Christian". If you ask us "are you Christian", we'll say "yes", but it's not the word we use.

Maybe that's totally different for evangelicals or some other mainline denomination. I wouldn't know.

I often experience this. I saw that a co worker had written something about God in their Twitter bio. "Are you a Christian?" "I'm a Catholic" they replied. Any other denomination would say "yes I'm a Christian" (there are no denominations in heaven, nor was there in the early church).

To understand this behaviour, it should be known that Catholics have introduced man made rules that they have additionally decided are not up for discussion (infallible) even if the Bible appears to say otherwise. Catholics teach that there is no salvation outside the church. By definition, this makes sense - the church is by definition a body of people who belong to Christ. However what the catholics actually mean is "the Roman Catholic church". Whether your average Catholic realises this or not it's debatable, but the common clarification "I'm a Catholic" is because they have absorbed a corrupt teaching that only catholics can be saved. Read this and the linked article at the bottom https://www.catholic.com/magazine/online-edition/is-there-re...

Edit: Nevermind apparently this is incorrect. This is just my take from trying to understand why we were Catholic and not Christian, and then avoiding being mistaken for 'Christian' later in life and not clarifying and staying in my lane. But I guess there is something else I don't understand going on.

'Christians' in the US don't consider Catholics 'Christians' (using quotes to show it's a group identifier based not solely on following Christs teachings). They (Christians) are also the newer splinter group. So Catholics have taken to identifying themselves as Catholics to 'stay in their lane' or to self identify to the 'Christians' that they aren't part of the accepted/in group. Catholics were lower status historically, look at the talk around Kennedy. Also Christians might not want to be friendly with Catholics but they would with Christians, so you out yourself as Catholic from the start to avoid that bullshit (so back to 'stay in your lane').

The two have very different approaches to religion, with Catholics following the 'love they neighbor' 'care for the poor' live Jesus' teachings and Christians building mega churches and following prosperity gospel. Or most upsetting to my grandma, the Christian holy roller stuff. Or more upsetting to the Christians Mother Mary in the Catholic church.

When I was a kid there was also a huge racial element. WASPs versus Catholic congregations made up of Italians, Irish, Filipinos, Latin Americans, Middle Easterners and Germans.

But from my experience it's largely the 'stay in your lane' thing. I've had people be friendly with me because since I was christian they assumed I was Christian christian, and when they found out I was Catholic they stopped talking to me (past tense as I'm not really religious).