What is meant by this is not, as Protestants like to view things, that there are many people in the Body of Christ some of whom are Catholic. That the Catholic Church is a subset of all who are "saved."
This is exactly wrong. The members of the Body of Christ are a subset of all attached to the Catholic Church. The Catholic Church is the larger of the two and all Christians are united to Her by their Baptisms.
SD
OK, I know what you mean when you say that all Christians are united to the Church by their baptisms. But how can the Catholic Church be larger than the Body of Christ? Or by "the Catholic Church" do you mean regular Catholics PLUS all baptized Christians? And the Body of Christ is a subset of this? I'm confused.