In reading various responses to Rod Dreher's announcement last week, I've noticed what I think are two views of the Church current among American Roman Catholics.
The first, which I'll call "denominationalism," is something like this: Sure, the Catholic Church has the fullness of truth, etc. But its function is to bring people close to Christ, and if they can get closer to Christ in another Christian denomination, more power to them.
The second, call it "anti-denominationalism," though it may just be an expression of triumphalism, sees the Church's possession of the fullness of truth as a doctrine that expresses the Church's superiority to other Christian bodies.
Both views insist on the uniqueness of the Catholic Church, but they incorrectly interpret this uniqueness in terms of the multiplicity of Christian churches, creeds, sects, and denominations.
What is missing is the practical awareness that the Church is a mystery. In the first chapter of Lumen Gentium, titled "The Mystery of the Church," the Church is called "the kingdom of Christ now present in mystery." The Catechism, in its treatment of the statement, "I believe in the Holy Catholic Church," has a subsection likewise called "The Mystery of the Church," in which it says:
The Church's first purpose is to be the sacrament of the inner union of men with God. Because men's communion with one another is rooted in that union with God, the Church is also the sacrament of the unity of the human race.
I think it's common to separate this thing called "the Church" that is the sacrament of unity with God and mankind from that other thing called "the Church" that is the Christian body comprising those in union with the Bishop of Rome. If the Church-that-is-a-mystery is, for practical purposes, imperceptible, then a whole host of questions lose their awkwardness and discomfort.
The Catholic Church is not the pre-eminent, or most correct, or only correct, or even one true Christian denomination. The Church is not a denomination at all, and to understand her in those terms is to misunderstand her.
I might add that of course "anti-denominationalists" don't think the Church is a Christian denomination. But to the extent that they express what the Church is in terms of her not being a denomination, they are making a mistake.