Catholic is a term generally used in relation to the members, beliefs and practices of the Roman Catholic Church. More broadly, it can be applied to Christian churches in general. Early Christians used the term to describe the whole undivided Church, the word's literal meaning is universal or whole. When divisions arose within the Catholic Church, the Church fathers and the historic creeds used it to distinguish the mainstream body of orthodox Christian believers from those adhering to sects or heretical groups.
Whilst the term is usually associated with the Roman Catholic Church, most Christians also lay claim to the term "catholic", including Eastern Orthodox and Protestants.
In countries that have been traditionally Protestant, Catholic will often be included in the official name of a particular parish church, school, hospice or other institution belonging to the Roman Catholic Church, in order to distinguish it from those of other denominations. For example, the name "St. Mark's Catholic Church" makes it clear that it is not an Episcopal or Lutheran church.
A millennium before the Protestant Reformation, St. Augustine wrote:
"In the Catholic Church, there are many other things which most justly keep me in her bosom. The consent of peoples and nations keeps me in the Church; so does her authority, inaugurated by miracles, nourished by hope, enlarged by love, established by age. The succession of priests keeps me, beginning from the very seat of the Apostle Peter, to whom the Lord, after His resurrection, gave it in charge to feed His sheep (Jn 21:15-19), down to the present episcopate.
- "And so, lastly, does the very name of Catholic, which, not without reason, amid so many heresies, the Church has thus retained; so that, though all heretics wish to be called Catholics, yet when a stranger asks where the Catholic Church meets, no heretic will venture to point to his own chapel or house.
- "Such then in number and importance are the precious ties belonging to the Christian name which keep a believer in the Catholic Church, as it is right they should ... With you, where there is none of these things to attract or keep me... No one shall move me from the faith which binds my mind with ties so many and so strong to the Christian religion... For my part, I should not believe the gospel except as moved by the authority of the Catholic Church."
— St. Augustine (AD 354–430) Against the Epistle of Manichaeus AD 397
Those who apply the term "Catholic Church" to all Christians indiscriminately find it objectionable that a term designating the whole Church (as an invisible entity) should be used to refer to one communion only. However, the Roman Catholic Church, which normally refers to itself simply as the Catholic Church — in 1992 it published a "Catechism of the Catholic Church" — sees itself (others would say: "asserts itself") as, basically, the continuation of the original Catholic or universal Church, from which other groups broke away at various times in history.
As well as the Roman Catholic Church, the Eastern Orthodox Churches, and the Oriental Orthodox Churches all see themselves as the "one holy catholic and apostolic Church" of the Nicene Creed. Others too who do not recognize the primacy of the Bishop of Rome use the term Catholic, but not in an exclusive sense, to describe their position, so as to distinguish it from a Calvinist or Puritan form of Protestantism. These include "High Church" Anglicans, known also as "Anglo-Catholics". Of course, Refomed Churches also consier themselves to be part of the Holy Catholic Church.
"Catholic Epistles" is another term for the General Epistles of the Christian New Testament in the Bible, which were addressed not to a particular city but to all in general. It is thus, strictly speaking, not an ecclesiastical term, being employed in the original broad sense of the Greek word from which "catholic" is derived. The epistles in question are James; First and Second Peter; First, Second, and Third Johnand Jude.
Capitalization is no sure guide to denominational affiliation. It may indicate formal affiliation with the Roman Catholic Church or it may not. Capitalization may merely indicate a wish to stress the holy and solemn nature of the spiritual body of believers and a desire for all Christians to be one.
It would be anachronistic to attribute significance to capitalization or lack of capitalization in printings of texts dating from before the last few centuries or in translations of those texts, since the originals were written in unmixed majuscule or minuscule letters. Translations even of modern texts into English often follow the usage of the original language. For instance, since French normally capitalizes only the first word of the title of an entity, the adjective "catholique", following the noun "Église", has a lower-case initial. Texts in Latin generally follow this usage, not the English practice.
Avoidance of usage
Some Protestant Christian Churches, avoid using the term completely. The Orthodox Churches share some of the concerns about Roman Catholic claims, but disagree with Protestants about the nature of the Church as one body. For some, to use the word "Catholic" at all is to appear to give credence to papal claims.