If we spotted a church located in a racially mixed neighborhood, and all its worshipers were white, we'd rightly be concerned. Or if we attended a church that focused so much on reaching young families that singles and seniors felt uncomfortable, that too would bother us. Most of us would suspect the first church to be racist and the second, exclusivist. Both suspicions might certainly be true. But there is more going on: Each church is failing to live out the gospel.
An essential part of the gospel is that it is catholic—that is, the Good News is given to all people. And the church the Holy Spirit creates is catholic.
Putting the matter like this may make some Christians squirm. Many Protestants affirm, either weekly or semi-regularly, the Nicene Creed, proclaiming, "We believe in one, holy, catholic, and apostolic church," but many balk at that word, catholic. (That's why in my own congregation, we use the word universal rather than catholic, because the original Greek term katholikos means "whole, entire, universal.")
When most of us hear the word catholic, we think of the Roman Catholic Church. By naming itself "Catholic," the Roman Church has claimed that it alone is the true universal church. Its argument is severalfold: (1) Only Rome has a unified, worldwide authority; (2) only Roman Catholics exist in every global region; (3) the Catholic Church is the only Christian tradition that dates back to the time of the apostles; (4) only the Catholic Church has the fullness of grace and truth; and (5) the majority of Christians in the world are Catholic. In short, they claim to have always been everywhere—truly catholic.
I personally cannot affirm that "catholic" ...