St. Alphonsus Liguori, Sermons (c. +1760): “How many are born among the pagans, among the Jєωs, among the Mohometans and heretics, and all are lost.”
Fr. Michael Muller, C.SS.R., The Catholic Dogma, pp. 217-218, 1888: “Inculpable or invincible ignorance has never been and will never be a means of salvation. To be saved, it is necessary to be justified, or to be in the state of grace. In order to obtain sanctifying grace, it is necessary to have the proper dispositions for justification; that is, true divine faith in at least the necessary truths of salvation, confident hope in the divine Savior, sincere sorrow for sin, together with the firm purpose of doing all that God has commanded, etc. Now, these supernatural acts of faith, hope, charity, contrition, etc., which prepare the soul for receiving sanctifying grace, can never be supplied by invincible ignorance; and if invincible ignorance cannot supply the preparation for receiving sanctifying grace, much less can it bestow sanctifying grace itself. ‘Invincible ignorance,’ says St. Thomas, ‘is a punishment for sin.’ (De, Infid. Q. x., art. 1).
Fr. Francisco de Vitoria, O.P., a famous 16th century Dominican theologian
“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.”
Pope St. Pius X, Acerbo Nimis (# 2), April 15, 1905:
“And so Our Predecessor, Benedict XIV, had just cause to write: ‘We declare that a great number of those who are condemned to eternal punishment suffer that everlasting calamity because of ignorance of those mysteries of faith which must be known and believed in order to be numbered among the elect.’”
Fr. De Smet, S.J., Jan. 26, 1838: “New priests are to be added to the Potawatomi Mission, and my Superior, Father Verhaegen gives me hope that I will be sent. How happy I would be could I spend myself for the salvation of so many souls, who are lost because they have never known truth!”
Pope Pius IX, Vatican I, Sess. 3, Chap. 3, 1870, on Faith: “But, since ‘without faith it is impossible to please God’ [Heb. 11:6] and to attain to the fellowship of His sons, hence, no one is justified without it…”
Pope Gregory XVI, Mirari Vos (# 13), Aug. 15, 1832: “With the admonition of the apostle, that ‘there is one God, one faith, one baptism’ (Eph. 4:5), may those fear who contrive the notion that the safe harbor of salvation is open to persons of any religion whatever. They should consider the testimony of Christ Himself that ‘those who are not with Christ are against Him,’ (Lk. 11:23) and that they disperse unhappily who do not gather with Him. Therefore, ‘without a doubt, they will perish forever, unless they hold the Catholic faith whole and inviolate (Athanasian Creed).”
End of debate. Period. Over. All non Catholics, whether they know the Gospel or not, are damned. If they were of Good Will God would have sent them a missionary or an angel (this has been docuмented dozens of times (even in the Bible (The ethiopian eunuch))).
Anyone who reads these, and still says a non-catholic can be saved, is in heresy.