Part of my job is to convince Protestants that the fullness of Christian faith and the apostolic deposit resides uniquely in the Catholic Church. The more a Protestant knows about this, the more responsible he or she will be to make a decision pro or con. Only God can finally determine if this is willful rebellion or invincible ignorance, and who will be saved or not.
Human beings simply don’t have that knowledge. It’s not our “game,” to figure out who is saved and who isn’t. This is the game that many Protestants play, but usually not Catholics. Only God ultimately knows who will be saved and who won’t be, so why do we spend so much time wrangling about it? It’s like the debate over predestination and free will that people endlessly carp on and on about. God knows who are His and who aren’t. He knows His sheep.
Catholic councils and authoritative magisterial statements (bishops, popes) deal with heresy, not who is saved and not saved. The two questions are quite distinct. Even if someone believes something objectively wrong (a heresy), there is a separate question of their subjective culpability in so doing, which involves a host of variables.
God is merciful and just, and He judges people based on what they know and what they do with true knowledge and revelation about Him: how they act upon it. For example, in every passage I have found about judgment day or the last days when all will be judged, people were judged based on what they did: not simply because they cited a “correct formula” such as “I’m saved by faith alone” or “TULIP is the gospel” or “I accepted Jesus into my heart as personal savior.”
We believe that the Catholic Church possesses the fullness of Christianity and that ideally all Christians should become Catholics; but it doesn’t follow that if they don’t, they are all damned, or that the Church has taught this. What is taught (properly understood) is that the Catholic Church is involved somehow in the salvation of every saved person. They don’t have to necessarily be aware of that, just as every person who is saved does not necessarily have to hear the gospel or know about Jesus Christ Himself. Yet if they are saved it was only because of Jesus. For instance, all who were saved before Jesus, in the old covenant, were saved by Him without yet knowing specifically about Him.
If anyone is saved, it’ll be on the basis of God’s grace, in faith, and because of some evidence of sanctity and the good works that must follow if true saving faith is present. We don’t frown on anything true in Protestantism (and there are tons of things that are true); we simply claim that we are the Church That Christ Founded: that possesses the fullness of Christian revelation and developed theology: handed down from Jesus to the apostles.
The flip side of that is when someone truly knows that Catholicism is true (all of it: not pick and choose, cafeteria-style “Catholicism”), and rejects it, we believe that he or she cannot be saved, because they would then be responsible for knowing the truth and deliberately rejecting it.
At the same time, it’s never preferable to leave someone in ignorance. It is always better to evangelize than not to, because knowing the fullness of Catholic truth is better for a person than not knowing it. God looks at the heart. He knows how folks would have responded had they known the Gospel. That’s part of His omniscience.
It doesn’t follow, though, that we shouldn’t evangelize. God wants us to play our part in spreading His message. He wants to include us in the whole enterprise. We’re commanded to do so. God will sort everything out in the end. Our main task is to be obedient, follow His commands, have faith, worship Him, and spread the Good News of the Gospel and the Church.
We don’t even have to assume that anyone is “lost.” We only have to assume that it is better for them to hear the gospel and message of the fullness of Catholicism, than to not hear it. God will determine in the end who is lost and who isn’t. We don’t have to — indeed, cannot — figure it out (thank heavens!). We simply need to be obedient about proclaiming the message. We share the truth and God can use that. The “chips” will fall where they may, but we’ve done our duty and have followed God’s command.
Where it becomes wrong and “counterproductive” is where (the false kind of) “ecumenism” becomes a cover for relativism and laxity concerning evangelization and apologetics. Too often that is the case, because it is the “either/or” mentality again. It’s thought that if we look to common ground and whatever unity we can achieve, therefore, no one should defend and proclaim one position as superior to another. It’s disdained as “proselytizing.”
No! We can do both. We are commanded to do both. The Church has stressed ecumenism in recent decades, but it has also stressed side-by-side with that, the truth that there is no salvation outside the Church. Both/and. I do both things myself, all the time. I practice both ecumenism (the authentic Catholic variety, not the theologically liberal, so-called “progressive” touchy-feely gobbledygook) and I also do my apologetics and evangelism. I don’t see the slightest contradiction, if they are both rightly understood. The Church doesn’t see it, either, and I follow her model and guidance.
From many passages in the Bible (I have found fifty of this nature), we know that Jesus judges on the last day based on actions. We also know how God looks at people who have different degrees of knowledge or ignorance, from this passage:
Romans 2:6-16 For he will render to every man according to his works:  to those who by patience in well-doing seek for glory and honor and immortality, he will give eternal life;  but for those who are factious and do not obey the truth, but obey wickedness, there will be wrath and fury.  There will be tribulation and distress for every human being who does evil, the Jew first and also the Greek,  but glory and honor and peace for every one who does good, the Jew first and also the Greek.  For God shows no partiality.  All who have sinned without the law will also perish without the law, and all who have sinned under the law will be judged by the law.  For it is not the hearers of the law who are righteous before God, but the doers of the law who will be justified.  When Gentiles who have not the law do by nature what the law requires, they are a law to themselves, even though they do not have the law.  They show that what the law requires is written on their hearts, while their conscience also bears witness and their conflicting thoughts accuse or perhaps excuse them  on that day when, according to my gospel, God judges the secrets of men by Christ Jesus.
If we apply this passage to, for example, a Muslim, if he or she has never heard of Christianity or never had a chance to properly understand it, and lives a life pretty much according to God’s moral law, they could very well be saved in the end. If, on the other hand, they have not only heard but understood Christianity (and Catholic Christianity) and know that it is true, and reject it, then they cannot be saved. There is only an “exception clause” due to ignorance, and the causes of that are myriad. God judges people by what they know and how they act upon it, and He is completely fair and just (“no partiality”).
As I read Romans 2, it seems to me that it is a general statement. “Gentiles” pretty much covers all who were not Jews. Nowhere in the passage do I see that Paul refers to these “Gentiles” necessarily being Christians. They certainly aren’t Jews, because they are “without the law” (2:12, 14, etc.). Nor is the Church mentioned in the entire chapter.
Now, it is true that some commentators apply their predisposition in theology to the passage and interpret it accordingly: some claiming that it is impossible to be saved without literally hearing about Christ and the gospel. But most commentators hold that it is referring to pagans or heathen.
Some think God is such a Being that He would either predestine millions to hell with no choice of their own, or predestine to hell all the multiple millions who have never heard of Jesus or the gospel simply because of that fact. I don’t think the Bible reveals such a merciless, arbitrary God. I think that it teaches that those who follow their conscience according to what they know, can be saved, even if they have never heard of Jesus or Christianity.
We must also distinguish between the following two propositions:
A) Whoever is saved is saved by the gospel of Jesus and His death on the cross, and must, additionally, formally be a member of the Catholic Church; otherwise he or she is damned.
B) Whoever is saved is saved by the gospel of Jesus and His death on the cross, and also by means of the Catholic Church founded by Jesus Christ, whether or not he or she literally hears the gospel of Jesus or about the Catholic faith, or becomes a formal member of the Catholic Church.
“No salvation ‘outside’ the Catholic Church” doesn’t reduce to the scenario of A; it means B. The confusion results from not grasping the following distinction:
A1) Whoever is directly affected by a particular cause must be personally aware of it.
B2) Whoever is directly affected by a particular cause can be so influenced whether or not he or she is aware of that cause.
Clearly, I think, it is a general truth that we need not be aware of all causes to be affected by them. For example, our house could catch on fire while we were asleep, but rains came and put the fire out. So we were saved by the rain without being aware of it. We didn’t have to be conscious of the rain to still be saved by it. Likewise, one can be saved by the blood of Jesus without being aware of it and without ever hearing the gospel. Jesus made salvation possible. Everyone who is saved is so, because of what Jesus did.
God gives every person a conscience and a knowledge of natural theology. All truly know that there is a God (Romans 1 and 2). What they do with this innate, God-given knowledge will determine if they are saved or not. But Jesus is the cause of the salvation. So is the Catholic Church, as no one is saved without being saved through the Catholic Church, whether they know that or not. They don’t have to know it in order for this to be the case.
Romans 2 is the clearest biblical teaching that I am aware of, with regard to this particular aspect of someone being saved who didn’t hear the Christian message of faith. St. Thomas Aquinas makes elaborate arguments about implicit faith, invincible ignorance, and so forth. Many of the Church fathers allude to the possibility of salvation without hearing the gospel. But if a person truly knows that Catholic teaching is the truth (only God knows all these particulars), and rejects it with a full consent of the will, then they will be damned and cannot be saved. They are judged by what they truly know, and how they have acted upon that knowledge.
St. Paul discusses the theme of unwitting ignorance in 1 Corinthians 12:2: “You know that when you were heathen, you were led astray to dumb idols, however you may have been moved.” In writing to the Ephesians, he implies again that many pagans are more ignorant than they are willfully opposed to truth:
Ephesians 2:11-13 Therefore remember that at one time you Gentiles in the flesh, called the uncircumcision by what is called the circumcision, which is made in the flesh by hands —  remember that you were at that time separated from Christ, alienated from the commonwealth of Israel, and strangers to the covenants of promise, having no hope and without God in the world.  But now in Christ Jesus you who once were far off have been brought near in the blood of Christ.
Unwitting ignorance is a common biblical theme. St. Peter, addressing the Jews in the temple, largely excused even the killing of Jesus in the same fashion: “now, brethren, I know that you acted in ignorance, as did also your rulers” (Acts 3:17; cf. Jesus on the cross: “Father, forgive them; for they know not what they do” — Luke 23:34). In one of his own epistles, Peter likewise stated:
“As obedient children, do not be conformed to the passions of your former ignorance,” (1 Peter 1:14). And again: “For it is God’s will that by doing right you should put to silence the ignorance of foolish men” (1 Peter 2:15). He casually mentions “the ignorant and unstable” (2 Peter 3:16).
But relentless manifested ignorance is something that should give one pause, since it can indeed lead to willful rejection of God and disobedience, as Peter argues in 2 Peter 2:10-22 (including Christians who fall away, in the last three verses). Peter refers to “reviling in matters of which they are ignorant” (2:12) and “waterless springs and mists driven by a storm” (2:17) and “men who have barely escaped from those who live in error” (2:18) and “slaves of corruption” (2:19).
St. Paul applied this state of mind or lack of knowledge to the Jews who rejected Christianity: “being ignorant of the righteousness that comes from God, and seeking to establish their own, they did not submit to God’s righteousness” (Romans 10:3). Paul even applied it to himself, referring to his earlier persecution of Christians: “I formerly blasphemed and persecuted and insulted him; but I received mercy because I had acted ignorantly in unbelief,” (1 Timothy 1:13). It should also be noted, however, that Paul (like Peter above) does also tie in ignorance with culpable unbelief:
Ephesians 4:17-19 Now this I affirm and testify in the Lord, that you must no longer live as the Gentiles do, in the futility of their minds;  they are darkened in their understanding, alienated from the life of God because of the ignorance that is in them, due to their hardness of heart;  they have become callous and have given themselves up to licentiousness, greedy to practice every kind of uncleanness. (cf. 2 Tim 3:1-9)
I would contend that these passages are merely additional instances of the sort of statement that Paul makes in Romans 1: not intended in the first place to be absolute or universal in application. The entirety of a person’s thought must be taken into consideration before we pontificate on the meaning of one instance of it. There are indeed people who have rebelled against God, and are, therefore, hardened and given over to self-conscious wickedness. They are referred to here.
But there are others who are simply ignorant. Since Paul (like Peter) refers to both classes, we know that he acknowledges both of them, and so we can’t sensibly take a view that Paul universally blames each and every pagan as culpably wicked and worthy of hell, and that he sees no other category where pagans (or today’s atheists, by extension) are concerned.
Paul says (again writing to highly pagan-influenced Greeks) that pagans did not “know” God or “know the truth” (in other words, they were ignorant):
1 Corinthians 1:20-22 Where is the wise man? Where is the scribe? Where is the debater of this age? Has not God made foolish the wisdom of the world?  For since, in the wisdom of God, the world did not know God through wisdom, it pleased God through the folly of what we preach to save those who believe.  For Jews demand signs and Greeks seek wisdom, (cf. 1 Cor 15:34: “…For some have no knowledge of God.…”)
Likewise, elsewhere, Paul writes:
Galatians 4:3-9 So with us; when we were children, we were slaves to the elemental spirits of the universe.  But when the time had fully come, God sent forth his Son, born of woman, born under the law,  to redeem those who were under the law, so that we might receive adoption as sons.  And because you are sons, God has sent the Spirit of his Son into our hearts, crying, “Abba! Father!”  So through God you are no longer a slave but a son, and if a son then an heir.  Formerly, when you did not know God, you were in bondage to beings that by nature are no gods;  but now that you have come to know God, or rather to be known by God, how can you turn back again to the weak and beggarly elemental spirits, whose slaves you want to be once more?
1 Thessalonians 4:5 not in the passion of lust like heathen who do not know God; (cf. James 4:17)
1 Timothy 2:4 who desires all men to be saved and to come to the knowledge of the truth. (cf. 4:3)
2 Timothy 2:25 correcting his opponents with gentleness. God may perhaps grant that they will repent and come to know the truth, (cf. Heb 10:26)
Men do not specifically know about the gospel of Jesus Christ; God uses Paul and others to spread this good news:
2 Corinthians 2:14 But thanks be to God, who in Christ always leads us in triumph, and through us spreads the fragrance of the knowledge of him everywhere. (cf. 2 Pet 1:16)
What formerly was mysterious has now been made known:
Ephesians 1:9 For he has made known to us in all wisdom and insight the mystery of his will, according to his purpose which he set forth in Christ. (cf. 1:17-18)
Ephesians 3:3-6 how the mystery was made known to me by revelation, as I have written briefly.  When you read this you can perceive my insight into the mystery of Christ,  which was not made known to the sons of men in other generations as it has now been revealed to his holy apostles and prophets by the Spirit;  that is, how the Gentiles are fellow heirs, members of the same body, and partakers of the promise in Christ Jesus through the gospel. (cf. 2 Pet 1:3)
Lastly, it should be noted that Jesus and Paul and John all rebuke those who falsely claim to “know” God, but who don’t prove it by their deeds):
Matthew 7:21 “Not every one who says to me, ‘Lord, Lord,’ shall enter the kingdom of heaven, but he who does the will of my Father who is in heaven.” (cf. 25:41-46)
Luke 6:46 “Why do you call me ‘Lord, Lord,’ and not do what I tell you?”
Titus 1:15-16 To the pure all things are pure, but to the corrupt and unbelieving nothing is pure; their very minds and consciences are corrupted.  They profess to know God, but they deny him by their deeds; they are detestable, disobedient, unfit for any good deed.
1 John 2:3-4 And by this we may be sure that we know him, if we keep his commandments.  He who says “I know him” but disobeys his commandments is a liar, and the truth is not in him;
1 John 3:24 All who keep his commandments abide in him, and he in them. And by this we know that he abides in us, by the Spirit which he has given us.
1 John 4:8 He who does not love does not know God; for God is love.
1 John 5:2 By this we know that we love the children of God, when we love God and obey his commandments.
(originally from 2012)