So were his 12 apostles, his 72 disciples, and in fact all of the early Church.
As He is the founder of the Church, He can be said to be a "member" of it, in the sense that He is the Head of His Body, the Church. Which was, at the time, the Jewish Christians: as Our Lord told the Samaritan woman at Jacob's Well, "Salvation is from the Jews."
To say "Roman Catholic" is something of an anachronism. The Church was "Catholic," tout court. It was only after the 16th Century that the term "Roman Catholic" gained any currency: there was a party of Anglicans who liked to call themselves "Anglo-Catholics," and they launched the correlative term, "Roman Catholics."--- to pin on the Catholics, who called themselves Catholic.
The Anglicans in England also called the Catholics "The Italian Mission." These terms were meant to be put-downs. That's not necessarily true now, but it was then.
I guess my point, however simple, was that we Christians are grafted onto the Jewish olive tree.
We become Jewish and worship the Jewish God (er, G-d):-).
I for one always feel very Jewish when I read Scripture. Not Roman Catholic or Protestant...just Jewish.
I know the Jews eyes have scales on them for our sakes...and those scales will be dropped at some point.
But we are grafted onto the Jewish vine...both Catholic and Protestant.
So the distinctive term "Roman Church" was not used before then, and that "Roman Catholic" should not be used?