Actually, the Catholic Church’s stance regarding the position of non-Catholic Christians and their relationship to the RCC has changed dramatically since Vatican II. Prior to Vatican II, popes had issued the following:
Pope Innocent III --4th Lateran Council: “There is but one universal Church of the faithful, outside of which no one at all can be saved.”
Pope Innocent’s remark may not phase your thinking, but I think the statements of Popes Boniface VIII and Eugene IV shed further insight as to how that statement was intended to mean:
Pope Boniface VIII–Unam Sanctam (One Holy).–“Urged by faith, we are obliged to believe and to maintain that the Church is one, holy, catholic, and also apostolic. We believe in her firmly and we confess with simplicity that outside of her there is neither salvation nor the remission of sins…In her then is one Lord, one faith, one baptism [Ephesians 4:5]. There had been at the time of the deluge only one ark of Noah, prefiguring the one Church, which ark, having been finished to a single cubit, had only one pilot and guide, i.e., Noah, and we read that, outside of this ark, all that subsisted on the earth was destroyed…Furthermore, we declare, we proclaim, we define that it is absolutely necessary for salvation that every human creature be subject to the Roman Pontiff.”
[Note: It is clear that Orthodox, Protestants, Messianic Jews do not submit to papal authority, which the pope stated is “absolutely necessary” for salvation. Unum Sanctum is often listed by the RCC as one of the “infallibles” papal declarations. If you accept the part that there is no salvation or forgiveness outside of the RCC, then you have to accept submission to the pope as essential for salvation as well.]
Pope Eugene IV–from “Cantate Domino”–“It [the Church] firmly believes, professes, and proclaims that those not living within the Catholic Church, not only pagans, but also Jews and heretics and schismatics cannot become participants in eternal life, but will depart ‘into everlasting fire which was prepared for the devil and his angels’ [Matt. 25:41], unless before the end of life the same have been added to the flock; and that the unity of the ecclesiastical body is so strong that only to those remaining in it are the sacraments of the Church of benefit for salvation, and do fastings, almsgiving, and other functions of piety and exercises of Christian service produce eternal reward, and that no one, whatever almsgiving he has practiced, even if he has shed blood for the name of Christ, can be saved, unless he has remained in the bosom and unity of the Catholic Church.”
