I suppose when one is being grammatically correct, and when one is talking about the true Church. But sometimes there are numerous Catholic Churches (like Eastern etc.) so what can one say Catholic Churches or the Catholic Churches, etc.?
If you follow the lead from the Catechism, the word “Church” is pretty much always capitalized, even when referring to the Eastern Catholic Churches or the Orthodox Churches.
Actually, you don’t use any grammatical function to denote the authenticity of the Church. When you are speaking about the universal, Catholic Church you use a capital “C”. When you are speaking about a parish (some use the word “church”), then you use a small “c”.
With regards to other denominations, you use a capital C if it is the name (e.g. “Synagogue Church of All Nations”) and you use a small c if you are referring to the building, i.e. the church.
The Catholic Church, in its documents, sometimes refers to Christian denominations without apostolic roots (i.e. non-Orthodox, non-Anglican) as “ecclesial communities”. But for the sake of being polite and to be understood by non-Catholics, you should address them as “churches” in common discourse.
Lower case c, for the particular; upper case c, for the universal.
The following are examples:
St. Paul is a Catholic church located on the next street.
Trinity is an Anglican church located on the next street.
Victory One is a Pentecostal church located on the next street.
The Catholic Church is the largest Christian denomination worldwide.
The Anglican Church is a Christian denomination undergoing controversial changes.
The Pentecostal Church is the fastest growing Christian denomination in the US.
There is The Church, and there are ecclesial communities. But precisely speaking, being Church means being One. Sans oneness, there is no Church.
I usually use upper C when talking about the Catholic Church or referring to a Catholic Church and lower c when talking about Protestant churches. It usually starts arguments with my Protestant friends on Facebook and I think that’s why I do it…maybe I should go to counseling or something but it’s a big brother gene I was born with. I’m sure this isn’t the response that you were looking for…but I feel better now that I’m out in the open with
I think this is right.
That’s how I always do it. If I’m talking about a physical building, denomination, or organization I use c. If I’m talking about the mystical body of Christ, I use C.
I quote the Catholic News Service Stylebook on Religion. Think of them as a religious version of the Associated Press Stylebook.
Do not capitalize unless it is used as part of the formal name of a building, a congregation or a denomination. Holy Redeemer Church, the United Methodist Church.
Lowercase in plural uses when two formal names are combined: Trinity Lutheran and Holy Redeemer churches, the Catholic and Methodist churches, Orthodox churches.
Lowercase church when it is used in an institutional or general theological sense: Father Smith said the church will not ordain women. The church is the people of God.
In references to local Catholic entities, generally use church for the building, parish for the organization and its people: The roof of St. Odilia Church was destroyed by a tornado. Members of St. Odilia Parish raised the money for a new roof in two days. It is also correct, however, to use church as a synonym for parish in such contexts: the members of St. Odilia Church.
Use a possessive form (for example: St. Mary’s Church) in a full name only if it is officially in the formal name. For names of Catholic churches in the United States, consult the Kenedy directory.
Catholic News Service (2013-02-22). CNS Stylebook on Religion: Reference Guide and Usage Manual