"There are many gifts," says St. Paul, "but the same Spirit." Paul might be called the apostle of diversity. "Are all prophets?" he asks, " Are all teachers? Do all work miracles?" He wants the Corinthians to stop bickering about the relative importance of their roles and rejoice in the variety of gifts. But the reason for the variety is to preach an invariant body of doctrine. And regarding that body Paul had zero tolerance for diversity, as we read in Galatians 1:9: "As we have said before, so now I say again, If any one is preaching to you a gospel contrary to that which you received, let him be anathema." Not, let him share the pulpit with an orthodox Catholic on alternate weekends; let him be excommunicated.
Go read the whole thing.