Deus, innocentiae restitutor et amator,
dirige ad te tuorum corda famulorum,
ut, quos de incredulitatis tenebris liberasti,
numquam a tuae veritatis luce discedant.
In the Gelasian Sacramentary this appeared on Saturday of the Octave of Easter. However, The Redactors changed infidelitatis to incredulitatis. A little "p.c." touch there, perhaps, and I don’t mean "post communionem".
O God, restorer and lover of innocence,
direct the hearts of your servants toward You,
that, those whom you freed from the shadows of religious disbelief
may never deviate from the light of Your truth.
Obviously, incredulitas or "religious disbelief" as the superb Lewis & Short Dictionary reveals, could apply to just about any religion, and even more obviously in the context of this Collect the religion in question is Christianity. Given the antiquity of this prayer, the original word infidelitas was a shot at the Jews and pagans still wandering in the shadows of errors.
Let us not forget the document Dominus Iesus issued from the Congregation for the Doctrine of the Faith over the signature of Cardinal Ratzinger in 2000. Here is a nice part:
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’”. If it is true that the followers of other religions can receive divine grace, it is also certain that objectively speaking they are in a gravely deficient situation in comparison with those who, in the Church, have the fullness of the means of salvation. However, “all the children of the Church should nevertheless remember that their exalted condition results, not from their own merits, but from the grace of Christ. If they fail to respond in thought, word, and deed to that grace, not only shall they not be saved, but they shall be more severely judged”. One understands then that, following the Lord’s command (cf. Mt 28:19-20) and as a requirement of her love for all people, the Church “proclaims and is in duty bound to proclaim without fail, Christ who is the way, the truth, and the life (Jn 14:6). In him, in whom God reconciled all things to himself (cf. 2 Cor 5:18-19), men find the fullness of their religious life”.
Just for kicks let’s stroll down memory lane to John Paul II’s 1998 document Ad tuendam fidem. I really like these bits:
Canon 598 – § 1. Those things are to be believed by divine and catholic faith which are contained in the word of God as it has been written or handed down by tradition, that is, in the single deposit of faith entrusted to the Church, and which are at the same time proposed as divinely revealed either by the solemn Magisterium of the Church, or by its ordinary and universal Magisterium, which in fact is manifested by the common adherence of Christ’s faithful under the guidance of the sacred Magisterium. All Christian faithful are therefore bound to avoid any contrary doctrines.
§ 2. Furthermore, each and everything set forth definitively by the Magisterium of the Church regarding teaching on faith and morals must be firmly accepted and held; namely, those things required for the holy keeping and faithful exposition of the deposit of faith; therefore, anyone who rejects propositions which are to be held definitively sets himself against the teaching of the Catholic Church.
Canon 1436 § 2 of the Code of Canons of the Eastern Churches, consequently, will receive an appropriate reference to canon 598 § 2, so that it will now read:
Canon 1436 – § 1. Whoever denies a truth which must be believed with divine and catholic faith, or who calls into doubt, or who totally repudiates the Christian faith, and does not retract after having been legitimately warned, is to be punished as a heretic or an apostate with a major excommunication; a cleric moreover can be punished with other penalties, not excluding deposition.
§ 2. In addition to these cases, whoever obstinately rejects a teaching that the Roman Pontiff or the College of Bishops, exercising the authentic Magisterium, have set forth to be held definitively, or who affirms what they have condemned as erroneous, and does not retract after having been legitimately warned, is to be punished with an appropriate penalty.
Did you notice that above we read "all Christian faithful" and not "Catholics"?
I think you should all organize Ad tuendam fidem anniversary parties for tomorrow, 18 May. Bring a questionable book and… well… have fun.