Q. 509. Are all bound to belong to the Church?
A. All are bound to belong to the Church, and he who knows the Church to be the true Church and remains out of it cannot be saved.
Q. 510. Is it ever possible for one to be saved who does not know the Catholic Church to be the true Church?
A. It is possible for one to be saved who does not know the Catholic Church to be the true Church, provided that person:
(1) Has been validly baptized;
(2) Firmly believes the religion he professes and practices to be the true religion, and
(3) Dies without the guilt of mortal sin on his soul.
Q. 516. Why can there be only one true religion?
A. There can be only one true religion, because a thing cannot be false and true at the same time, and, therefore, all religions that contradict the teaching of the true Church must teach falsehood. If all religions in which men seek to serve God are equally good and true, why did Christ disturb the Jewish religion and the Apostles condemn heretics?
Q. 510. Is it ever possible for one to be saved who does not know the Catholic Church to be the true Church?
A. It is possible for one to be saved who does not know the Catholic Church to be the true Church, provided that person:
(1) Has been validly baptized;
(2) Firmly believes the religion he professes and practices to be the true religion, and
(3) Dies without the guilt of mortal sin on his soul.
Wouldn't that cover every religion on earth? If a Buddhist firmly believes his religion is the true religion will he be saved? What about the Islamist? What about the Hindu? The Satanist?