When we use the word Catholic we think of it in denominational terms. Even if the Roman Catholic Church eschews the idea that they are a denomination, they are in fact one -- whether they like it or not. They are but one branch of the Christian community.
The word "catholic" speaks of universality. Thus, it is proper to speak of the Roman Catholic Church. The word Roman modifies the word Catholic. In my time in England I spent time working in the Bodleian Library, reading through letters and papers that flowed between Thomas Brett, a Nonjuror, and a wide variety of other correspondents, most of whom shared his Nonjuring commitments. The Nonjurors are a rather obscure group of late seventeenth through eighteenth century dissenters from the current religious and political establishment in England during that period. I won't go into detail on the Nonjurors -- if interested you can read my online article about their theology -- but I bring them up because they, even in their own schismatic behavior (who was schismatic is a matter of opinion, of course), they sought to give voice to a principle of catholicity, one that was rooted in a connection to the practices and beliefs of the Primitive Church. By Primitive Church, unlike members of my own Disciples tradition, they meant the church that existed in the first five to six centuries. They made great use of the principle of Vincent of Lerins -- semper, ubique, et ab omnibus (always, everywhere, and by everyone) -- to under gird their proclamation of a vision that was to be truly Catholic. It wasn't Catholic in the Roman sense, but in a broader sense, one that sought to place the church within the broader history and tradition of Christianity. Now, there are dangers in this. The Nonjurors are good examples because they sought to make certain practices, especially liturgical practices, necessary for proper faith. They became fundamentalists of the Patristic kind.
I am by most markers part of the Protestant Tradition, that is, my own faith journey has taken place within that branch of the Christian community that takes its origins from the Reformation. I was born and bread Episcopalian, which like the Church of England, derives from the English Reformation. I am a Disciple, a community, that both takes cues from and eschews the Presbyterian Tradition. Both traditions have been influenced by John Calvin. My Nonjuror friends sought to avoid the Calvinist contribution by rooting their beliefs and practices in the Reforms that came about prior to the coming of Martin Bucer and Peter Martyr.
So, back to being Catholic, a theme that I want to dwell upon for a few posts, especially leading up to World Communion Sunday, I'd like to suggest that whether Roman, Orthodox, Protestant, that it is important that we embrace the principal espoused in the Creeds that we are part of the "One Holy Catholic and Apostolic Church." As a Disciple pastor my ordination may not derive from direct episcopal (apostolic) succession, but in terms of faith tradition, I am part of that One Catholic Church. By worshiping these past two weeks in Anglican Cathedrals (Christ Church, Oxford, and St. Paul's London), and especially as I took Communion in these communities (if anyone wants to raise any questions about my ability to do this, I should note that I was confirmed into the Episcopal Church, so that indelible mark should still be holding strong), I found myself receiving this witness of Catholicity.
Can you, with me, affirm that to be a Christian is to be Catholic?