Many Catholics can perhaps still remember a time when the explanation from Catholic bishops and popes about the Catholic Church’s stance on salvation outside the church was little more than a reaffirmation of the traditional and literal understanding of the ancient Cyprian formula extra ecclesiam nulla salus [outside the Church there is no salvation]. Until the official progressive view endorsed by Vatican II, the traditional understanding of this ancient phrase was fairly straightforward—if you are not visibly a member of the Catholic Church you were excluded from salvation. Cyprian’s analogy was of Noah’s ark—just like Noah’s contemporaries had to be inside the Ark to be saved from the flood, so one has to be “inside” the Catholic Church to be saved.
This interpretation of the Cyprian formula, however, in spite of its historical pedigree and centrality in the Catholic Tradition in per-modern history, was reinterpreted at Vatican II. Any genuine doctrinal development that takes place on the official level in the Catholic Church is preceded by progressive views. To understand this development, however, we must first understand not only the Cyprianic formula, but the theological rationale behind it. It was argued early on (most notably by Augustine) that since Jesus and the Apostles taught that saving grace came through the sacraments (Mk 16:16; Jn 6:53; Acts 2:38), the Church is therefore necessary for salvation, for she administers the sacraments as Jesus instructed. Thus the formula was tied initially to a sacerdotal soteriology. If the progressive view was going to reshape traditional Catholic beliefs about adherents of other religions, this sacerdotal logic had to be addressed.
Vatican II still dogmatically echoes the tradition that salvation comes through Jesus Christ and that this salvation is mediated through the Church. For example:
Basing itself on scripture and tradition, [this holy Council] teaches that the Church, a pilgrim now on earth, is necessary for salvation: the one Christ is mediator and the way of salvation; he is present to us in his body which is the Church. He himself explicitly asserted the necessity of faith and baptism (cf. Mk. 16:16; Jn. 3:5), and thereby affirmed at the same time the necessity of the Church which men enter through baptism as through a door.
The analogy used here is also similar to the traditional analogy of Noah’s Ark—baptism is the “door” one must go through to be saved. Nevertheless, whereas the Cyprianic formula was intended to be interpreted as meaning that visible membership in the Catholic Church was necessary for salvation, Vatican II only requires this as a precondition for the fullness of salvation, not salvation itself. In the Vatican II documents, different levels of incorporation into salvation are tied specifically to different ways non-Catholics can be incorporated into the Catholic Church without their knowing it.
Fully incorporated into the Church are those who … [are] joined in the visible structure of the Church of Christ, who rules her through the Supreme Pontiff and the bishops. …
Catechumens who, moved by the Holy Spirit, desire with an explicit intention to be incorporated into the Church, are by that very intention joined to her. …
The Church knows that she is joined in many ways to the baptized who are honored by the name of Christian, but who do not however profess the Catholic faith in its entirety or have not preserved unity or communion under the successor of Peter. … these Christians are indeed in some real way joined to us in the Holy Spirit for, by his gifts and graces, his sanctifying power is also active in them…
Finally, those who have not yet received the Gospel are related to the People of God in various ways. There is, first, that people to which the covenants and promises were made [Jews] … But the plan of salvation also includes those who acknowledge the Creator, in the first place amongst whom are the Moslems [sic] … Nor is God remote from those who in shadows and images seek the unknown God, since he gives to all men life and breath and all things (cf. Acts 17:25-28), and since the Savior wills all [people] to be saved (cf. 1 Tim 2:4). Those who, through no fault of their own, do not know the Gospel of Christ or his Church, but who nevertheless seek God with a sincere heart, and, moved by grace, try in their actions to do his will as they know it through the dictates of their conscience—those too may achieve eternal salvation. 
Since Baptism is necessary for salvation, all persons saved without a Christian baptism are considered incorporated into the Catholic Church by a baptismo implicitum (an implicit baptism). This way, the Catholic Church still holds to the wording of the Cyprianic formula without requiring the traditional literal interpretation, thus yielding the original formula dangerously misleading for Catholics unfamiliar with the developments of Vatican II.
This new inclusivist framework still holds that salvation is only through Christ and the Church, and views whatever goodness or truth inherent within other religions and their adherents as finding their true fulfillment in Christ. In this sense, other religions can be seen as preparatio evangelica [a preparation for the fullness of the gospel]. Although whatever good found in other religions is “preserved … purified, raised up, and perfected” by the Catholic faith, the Church still “snatches them from the slavery of error” when she incorporates them more fully into Christ and “each disciple of Christ has the obligation of spreading the faith to the best of his ability.” Gaudium et Spes nevertheless adds a comforting qualifier about the necessity of evangelism by teaching that “the Holy Spirit in a manner known only to God offers to every [person] the possibility of being associated with this paschal mystery.”
Popes and Catholic theologians have given various assessments of Vatican II’s theology of religions. Karl Rahner’s theology of “anonymous Christianity” had a major influence on the question of whether other religions can have salvific potency. He believed Vatican II left the question “open” and does not finally resolve all ambiguity. Kärkkäinen says Paul Knitter represents “one extreme” that sees mainstream Catholicism as implicitly affirming a pluralist position. The majority of post-Conciliar developments, however, “usually hold the more restrictive view according to which followers of other religions may be saved but other religions as such do not have salvific structure.” Theologians like Gavin D’Costa have become outspoken critics of the pluralist interpretation of Knitter and others. Later encyclicals such as Pope Paul VI’s Evangelii Nuntiandi (1975) and John Paul II’s Redemptoris Missio (1990) can be seen as pastoral correctives against a de-emphasis on Christ and “the church’s central role in the history of salvation” and “practices of interreligious dialogue that stressed the commonalities among religions rather than Christian uniqueness.”
In sum, the mainline Catholic interpretation of Vatican II can be recapped this way: “Followers of other religions can find salvation, but such salvation is found finally and fully in Christ and his church.” In this manner, Catholics believe that because salvation comes through Jesus Christ via the Church, Catholics have an obligation and duty to proclaim the Christian faith and seek converts. On the other hand, because God desires the salvation of all people, his grace is at work outside the Church, leading people who remain in other religions to be nevertheless “incorporated” into the Church in various ways.
Bradley R. Cochran
 There were certain exceptions to this that one might easily anticipate. For example, if you had accepted the Church, embraced her, and were being prepared for baptism, then suddenly died before you were actually baptized, you were considered as baptized anyway (by a “baptism of desire”). Or if you had accepted the Catholic message but died a martyr’s death before you happened to be baptized, you could still be considered as baptized (by a “baptism of blood”). But these exceptions were for those who had explicitly accepted Catholicism or the message of Catholics but who were not yet baptized, not for people who followed other religions. There was a stronger precedent, however, for the doctrinal development that took place at Vatican II. Kärkkäinen, for example, notes that “as late as 1943, the highly acclaimed papal encyclical entitled Mystici Corporis (“the Mystical Body”) by Pius XII still held to the view that only ‘true’ Catholics are saved,” but he admits also that this same encyclical leaves open the door of salvation for those who have no access to the gospel. Veli-Matti Kärkkäinen, An Introduction to Theology of Religions: Biblical, Historical, and Contemporary Perspectives (Downers Grove, Illinois: InterVarsity Press, 2003), 111-12. Mystici Corporis taught that people who have no access to the gospel can “by a certain unconscious desire and longing” be “ordained to the mystical Body of the Redeemer.” Though initially applied only to those who have no access to the gospel, Vatican II would adopt and refine the logic used in this document in order to explain how people who remain as adherents of other religions might also still achieve eternal salvation.
 Vatican Council II: The Conciliar and Post Conciliar Documents, new revised edition, ed. Austin Flannery, O.P. (Northport, New York: Costello Publishing, 1975, fifth printing 2004). The documents most relevant to the Catholic theology of religions are: Nostra Aetate (NA), Ad Gentes (AG), Gaudium et Spes (GS), and Lumen Gentium (LG).
 Lumen Gentium (LG) 14.
 LG 14-16.
 This is generally known as a “fulfillment theory” of religions. “That is to say, other religions are ‘fulfilled’ (find their completion and perfection) in Christianity.” Paul Hedges, Controversies in Interreligious Dialogue and the Theology of Religions (London, UK: SCM Press, 2010), 23.
 Kärkkäinen, An Introduction to Theology of Religions, 117.
 LG 17.
 Kärkkäinen, An Introduction to Theology of Religions, 115.
 Ibid., 118.
 Ibid., 117.
 Gavin D’Costa, ed. Christian Uniqueness Reconsidered: The Myth of a Pluralistic Theology of Religions (Maryknoll, New York: Orbis, 1990).
 Kärkkäinen, An Introduction to Theology of Religions, 120.
 Ibid., 120.