http://www.cin.org/users/james/ebooks/master/pius/pcreed09.htm
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."
33 Q: Can the Church err in what she proposes for our belief?
A: No, the Church cannot err in what she proposes for our belief, since according to the promise of Jesus Christ she is unfailingly assisted by the Holy Ghost.
34 Q: Is the Catholic Church infallible, then?
A: Yes, the Catholic Church is infallible, and hence those who reject her definitions lose the faith and become heretics.
35 Q: Can the Catholic Church be destroyed or perish?
A: No; the Catholic Church may be persecuted, but she can never be destroyed or perish. She will last till the end of the world, because Jesus Christ, as He promised, will be with her till the end of time.
36 Q: Why is the Catholic Church so persecuted?
A: The Catholic Church is so persecuted because even her Divine Founder, Jesus Christ, was thus persecuted, and because she reproves vice, combats the passions, and condemns all acts of injustice and all error.
37 Q: Has a Catholic any other duties towards the Church?
A: Every Catholic ought to have a boundless love for the Church, ought to consider himself infinitely honored and happy in belonging to her, and ought to labor for her glory and advancement by every means in his power.