…The “seeds of truth” present and active in the various religious traditions are a reflection of the unique Word of God, who “enlightens every man coming into world” (cf. Jn 1:9) and who became flesh in Christ Jesus (cf. Jn 1:14). They are together an “effect of the Spirit of truth operating outside the visible confines of the Mystical Body” and which “blows where it wills” (Jn 3:8; cf. Redemptor hominis, nn. 6, 12).
…It must first be kept in mind that every quest of the human spirit for truth and goodness, and in the last analysis for God, is inspired by the Holy Spirit. The various religions arose precisely from this primordial human openness to God. At their origins we often find founders who, with the help of God’s Spirit, achieved a deeper religious experience. Handed on to others, this experience took form in the doctrines, rites and precepts of the various religions.
In every authentic religious experience, the most characteristic expression is prayer. Because of the human spirit’s constitutive openness to God’s action of urging it to self-transcendence, we can hold that “every authentic prayer is called forth by the Holy Spirit, who is mysteriously present in the heart of every person”.
…Normally, “it will be in the sincere practice of what is good in their own religious traditions and by following the dictates of their own conscience that the members of other religions respond positively to God’s invitation and receive salvation in Jesus Christ, even while they do not recognize or acknowledge him as their Saviour (cf. Ad gentes, nn. 3, 9, 11)”
…For the reasons mentioned here, the attitude of the Church and of individual Christians towards other religions is marked by sincere respect, profound sympathy and, when possible and appropriate, cordial collaboration. This does not mean forgetting that Jesus Christ is the one Mediator and Saviour of the human race. Nor does it mean lessening our missionary efforts, to which we are bound in obedience to the risen Lord’s command: “Go therefore and make disciples of all nations, baptizing them in the name of the Father and of the Son and of the Holy Spirit” (Mt 28:19). The attitude of respect and dialogue is instead the proper recognition of the “seeds of the Word” and the “groanings of the Spirit”."
-Pope John Paul II
"as it is written: 'None is righteous, no, not one; no one understands; no one seeks for God. All have turned aside; together they have become worthless; no one does good, not even one.'...for all have sinned and fall short of the glory of God, and are justified by his grace as a gift, through the redemption that is in Christ Jesus, whom God put forward as a propitiation by his blood, to be received by faith." Romans 3:10-12,23-25