St. Augustine, Tractate 89, on John 15:22-23- “What, then, does He [Jesus] mean by the words, If I had not come and spoken unto them, they had not had sin? [John 15:22] Was it that the Jews were without sin before Christ came to them in the flesh? Who, though he were the greatest fool, would say so?.. But when He went on to say, But now they have no excuse for their sin, some may be moved to inquire whether those to whom Christ neither came nor spoke, have an excuse for their sin. For if they have not, why is it said here that these had none, on the very ground that He did come and speak to them? And if they have, have they it to the extent of thereby being barred from punishment, or of receiving it in a milder degree? To these inquiries, with the Lord’s help and to the best of my capacity, I reply, that such have an excuse, not for every one of their sins, but for this sin of not believing on Christ, inasmuch as He came not and spoke not to them.”
Code:
Fr. Francisco de Vitoria, O.P., a famous 16th century Dominican theologian, summed up the traditional teaching of the Catholic Church on this topic very well. Here is how he put it:
“When we postulate invincible ignorance on the subject of baptism or of the Christian faith, it does not follow that a person can be saved without baptism or the Christian faith. For the aborigines to whom no preaching of the faith or Christian religion has come will be damned for mortal sins or for idolatry, but not for the sin of unbelief. As St. Thomas says, however, if they do what in them lies [in their power], accompanied by a good life according to the law of nature, it is consistent with God’s providence that he will illuminate them regarding the name of Christ.”
St. Augustine (426): “Consequently both those who have not heard the gospel and those who, having heard it, and having been changed for the better, did not receive perseverance… none of these are separated from that lump which is known to be damned, as all are going… into condemnation.”
2 Corinthians 4:3: “And if our gospel be hid, it is hid to them that are lost, in whom the god of this world [Satan] hath blinded the minds of unbelievers, that the light of the gospel of the glory of Christ, who is the image of God, should not shine unto them.”
Pope Eugene IV, Council of Florence, “Cantate Domino,” 1441, ex cathedra: “The Holy Roman Church firmly believes, professes and preaches that all those who are outside the Catholic Church, not only pagans but also Jews or heretics and schismatics, cannot share in eternal life and will go into the everlasting fire which was prepared for the devil and his angels, unless they are joined to the Church before the end of their lives; that the unity of this ecclesiastical body is of such importance that only for those who abide in it do the Church’s sacraments contribute to salvation and do fasts, almsgiving and other works of piety and practices of the Christian militia produce eternal rewards; and that nobody can be saved, no matter how much he has given away in alms and even if he has shed blood in the name of Christ, unless he has persevered in the bosom and unity of the Catholic Church.”