Question: How can the church be infallible, if She changed her view on Salvation outside the Church?
Answer: The answer is that the Church has NOT changed its view on salvation. No one who is outside the Catholic Church can be saved. Only those who are part of the Church have any hope of salvation. The Second Vatican Council (VCII) makes this clear in The Dogamatic Constitution on the Church (Lumen Gentium), paragraph 14:
14. This sacred Council wishes to turn its attention firstly to the Catholic faithful. Basing itself upon Sacred Scripture and Tradition, it teaches that the Church, now sojourning on earth as an exile, is necessary for salvation. Christ, present to us in his body, which is the Church, is the one Mediator and the unique way of salvation. In explicit terms he himself affirmed the necessity of faith and Baptism (cf. Mk 16:16; Jn 3:5) and thereby affirmed also the necessity of the Church, for through Baptism as through a door men enter the Church. Whosoever, therefore, knowing that the Catholic Church was made necessary by Christ, would refuse to enter or to remain in it, could not be saved.
This has always been the teaching of the Church and has not changed. Those who have not been validly baptized (which includes many Protestants whose religions do not b practice the sacraments in a valid manner) will go to Hell. If they are not guilty of serious sin, it is the majority opinion of Catholic scholars that they will go only to the edge or limbus of Hell. This has traditionally been known as "Limbo." There they may suffer no greater punishment than the absence of the beatific vision. Most believe that they will have natural happiness which is not the same as the supernatural blessedness of heaven.
Validly baptized persons who are in material schism from the Catholic Church cannot go to Limbo. They will either go to Heaven (possibly through Purgatory, if they need it) or to Hell. Material heretics or schismatics (i.e., those who are outside the Church through no fault of their own) are by definition not guilty of the sin of false religion and so cannot be damned for that alone. Apostates and formal heretics & schismatics, (i.e., those who have knowingly left the Church) are guilty of some sin of irreligion. If it meets the criteria for mortal sin, they can be damned for that alone.
From the times of the Early Church, it has been recognized that some people might receive sanctifying grace who have died while awaiting Baptism (e.g., catechumens preparing for reception into the Church- Baptism of Desire) or who were martyred for Christ before being sacramentally baptized (Baptism of Blood).
A new development in the last 200 years (really starting with Pope Pius IX, but brought to fruition at VCII) is that the Magisterium has acknowledged the possibility that some unbaptized persons may be saved by the grace of God even though they have never formally sought baptism. The possibility exists that they have responded sufficiently to the non-justifying actual graces which God has granted them in a sincere hope of seeking him and pleasing him so that God will generously grant them sanctifying grace. This is a possibility only. This was a further development and refinement of previously defined teaching.
The strong statements from previous Church Councils and other sources about "no salvation outside the Catholic Church" always assumed the legitimacy of Catholic moral theology as the normative limiting factor to what their teaching concerning the sins against true religion. It was always understood that not every heretic was a willful heretic, and that culpability for sin could be mitigated by either ignorance or coercion.
Art Sippo
The Catholic Legate