Pope St. Pius X made a distinction between the living members of the Church and the dead members in his Catechism.
21 Q: What is the constitution of the Church of Jesus Christ?
A: The Church of Jesus Christ has been constituted as a true and perfect Society; and in her we can distinguish a soul and a body.
**22 Q: In what does the Soul of the Church consist? **
A: The Soul of the Church consists in her internal and spiritual endowments, that is, faith, hope, charity, the gifts of grace and of the Holy Ghost, together with all the heavenly treasures which are hers through the merits of our Redeemer, Jesus Christ, and of the Saints.
**23 Q: In what does the Body of the Church consist? **
A: The Body of the Church consists in her external and visible aspect, that is, in the association of her members, in her worship, in her teaching-power and in her external rule and government.
24 Q: To be saved, is it enough to be any sort of member of the Catholic Church?
A: No, to be saved it is not enough to be any sort of member of the Catholic Church; it is necessary to be a living member.
**25 Q: Who are the living members of the Church? **
A: The living members of the Church are the just, and the just alone, that is, those who are actually in the grace of God.
**26 Q: And who are the dead members? **
A: The dead members of the Church are the faithful in mortal sin.
**27 Q: Can one be saved outside the Catholic, Apostolic and Roman Church? **
A: No, no one can be saved outside the Catholic, Apostolic Roman Church, just as no one could be saved from the flood outside the Ark of Noah, which was a figure of the Church.
**28 Q: How, then, were the Patriarchs of old, the Prophets, and the other just men of the Old Testament, saved? **
A: The just of the Old Testament were saved in virtue of the faith they had in Christ to come, by means of which they spiritually belonged to the Church.
**29 Q: But if a man through no fault of his own is outside the Church, can he be saved? **
A: If he is outside the Church through no fault of his, that is, if he is in good faith, and if he has received Baptism, or at least has the implicit desire of Baptism; and if, moreover, he sincerely seeks the truth and does God’s will as best he can such a man is indeed separated from the body of the Church, but is united to the soul of the Church and consequently is on the way of salvation
**30 Q: Suppose that a man is a member of the Catholic Church, but does not put her teaching into practice, will he be saved? **
A: He who is a member of the Catholic Church and does not put her teaching into practice is a dead member, and hence will not be saved; for towards the salvation of an adult not only Baptism and faith are required, but, furthermore, works in keeping with faith.
**31 Q: Are we obliged to believe all the truths the Church teaches us? **
A: Yes, we are obliged to believe all the truths the Church teaches us, and Jesus Christ declares that he who does not believe is already condemned.
32 Q: Are we also obliged to do all that the Church commands?
A: Yes, we are obliged to do all that the Church commands, for Jesus Christ has said to the Pastors of the Church: “He who hears you, hears Me, and he who despises you, despises Me.”