Second: The Church, according to Vatican II, is not only the Mystical Body of Christ, but also the People of God from the earliest monotheist faith of Abraham to the end of the ages and in the cultures which receive Christ. Let me add that according to the CDF declaration Dominus Iesus or "The Lord Jesus" approved for publication by Blessed John Paul II in 2000, the following is stated:
"Above all else, it must be firmly believed that 'the Church, a pilgrim now on earth, is necessary for salvation: the one Christ is the 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'.77 This doctrine must not be set against the universal salvific will of God (cf. 1 Tim 2:4); “it is necessary to keep these two truths together, namely, the real possibility of salvation in Christ for all mankind and the necessity of the Church for this salvation”. The Church is the “universal sacrament of salvation”, since, united always in a mysterious way to the Saviour Jesus Christ, her Head, and subordinated to him, she has, in God's plan, an indispensable relationship with the salvation of every human being. For those who are not formally and visibly members of the Church, 'salvation in Christ is accessible by virtue of a grace which, while having a mysterious relationship to the Church, does not make them formally part of the Church, but enlightens them in a way which is accommodated to their spiritual and material situation. This grace comes from Christ; it is the result of his sacrifice and is communicated by the Holy Spirit'; it has a relationship with the Church, which 'according to the plan of the Father, has her origin in the mission of the Son and the Holy Spirit'.
21. With respect to the way in which the salvific grace of God — which is always given by means of Christ in the Spirit and has a mysterious relationship to the Church — comes to individual non-Christians, the Second Vatican Council limited itself to the statement that God bestows it 'in ways known to himself'. Theologians are seeking to understand this question more fully. Their work is to be encouraged, since it is certainly useful for understanding better God's salvific plan and the ways in which it is accomplished. However, from what has been stated above about the mediation of Jesus Christ and the 'unique and special relationship84 which the Church has with the kingdom of God among men — which in substance is the universal kingdom of Christ the Saviour — it is clear that it would be contrary to the faith to consider the Church as one way of salvation alongside those constituted by the other religions, seen as complementary to the Church or substantially equivalent to her, even if these are said to be converging with the Church toward the eschatological kingdom of God." The Declaration continues:"Certainly, the various religious traditions contain and offer religious elements which come from God, and which are part of what “the Spirit brings about in human hearts and in the history of peoples, in cultures, and religions”. Indeed, some prayers and rituals of the other religions may assume a role of preparation for the Gospel, in that they are occasions or pedagogical helps in which the human heart is prompted to be open to the action of God. One cannot attribute to these, however, a divine origin or an ex opere operato salvific efficacy, which is proper to the Christian sacraments.88 Furthermore, it cannot be overlooked that other rituals, insofar as they depend on superstitions or other errors (cf. 1 Cor 10:20-21), constitute an obstacle to salvation.
22. With the coming of the Saviour Jesus Christ, God has willed that the Church founded by him be the instrument for the salvation of all humanity (cf. Acts 17:30-31). This truth of faith does not lessen the sincere respect which the Church has for the religions of the world, but at the same time, it rules out, in a radical way, that mentality of indifferentism “characterized by a religious relativism which leads to the belief that ‘one religion is as good as another'”. I have removed the notes for easier reading but you may wish to look again at this rich document. See http://www.vatican.va/roman_curia/congregations/cfaith/documents/rc_con_cfaith_doc_20000806_dominus-iesus_en.html.
When we think of Christian unity which is a dear goal for all committed Christians, let's recall to mind that the doctrinal and liturgical developments in the entire Catholic Church remain a treasure to hold.
For many reasons, historical and theological, I remain convinced that every human person who seriously searches for the truth is, according to Dominus Iesus, in a mysterious way, linked to the Mystery of the Church i.e. The Catholic Church. That is how open and far-reaching is Catholicism. Henri de Lubac certainly contributed to such openness.