If we Catholics often lack a passion for bringing people to Christianity in general, I think it's even truer that on the whole we lack a passion for bringing people to Catholicism in particular. I'm not saying that we just don't care. Most fellow Catholics I know, at least the orthodox ones, do think it would be ideal if everyone became Catholic. However there's no real sense of urgency behind this admission. There is a sort of lukewarmness about it, of which I too can be guilty. It wasn't always like this. In times past, Catholics were quite zealous about bringing people to Christ specifically by way of His visible Body--the Church.
What has changed? Well, for one thing, the Church has clarified Her teaching in ways that were often glossed over before. At one time, the average Catholic was under the impression that the overwhelming majority--if not the entirety--of non-Catholics went to Hell, regardless of whether they embraced faith in Christ in some other way. This is because of the teaching (which is still dogma, as dogma never changes) "Outside of the Church there is no salvation." But it was always the teaching of the Church that those who were non-Catholic through no fault of their own could be saved. Pope Pius IX said the following in the mid 1800's in his encyclical Quanto conficiamur moerore:
It is known to us and to you that those who are in invincible ignorance of our most holy religion, but who observe carefully the natural law, and the precepts graven by God upon the hearts of all men, and who being disposed to obey God lead an honest and upright life, may, aided by the light of divine grace, attain to eternal life; for God who sees clearly, searches and knows the heart, the disposition, the thoughts and intentions of each, in His supreme mercy and goodness by no means permits that anyone suffer eternal punishment, who has not of his own free will fallen into sin. (emphasis mine)"Invincible Ignorance" is that sort of ignorance of which Jesus said "Forgive them, for they know not what they do," or, in another verse, "If you were blind, you would have no sin." It's when someone fails to see the truth, but it's not their fault. For example, if a Protestant was genuinely convinced that there was no reason to give Catholicism a chance, or if he did look into it and was genuinely convinced it just isn't true--despite his sincere efforts to give it a fair shot--then it might be said that his not believing in Catholicism is to no fault of his own. He's done what he could, and for mysterious reasons simply hasn't been able to come to the same conclusions we Catholics have.
In modern times, the Church has simply emphasized this more than She did one hundred years ago. The Catechism of the Catholic Church has this to say, after first having confirmed that heresy (wrong beliefs) and schism (separating from the Church) are sins:
818 "However, one cannot charge with the sin of the separation those who at present are born into these communities [that resulted from such separation] and in them are brought up in the faith of Christ, and the Catholic Church accepts them with respect and affection as brothers . . . . All who have been justified by faith in Baptism are incorporated into Christ; they therefore have a right to be called Christians, and with good reason are accepted as brothers in the Lord by the children of the Catholic Church."272So it's easy to see, then, why so many Catholics these days are prone to feeling cozy with the thought of our Protestant (or Orthodox) brothers and sisters never crossing over into the Church. Unlike before, the Church has spelled out to us plainly that our brothers and sisters outside of the Church are still Christians and that, if they're outside of the Church to no fault of their own, can be saved. If they're not in danger of hell, we seem to reason, then what's the urgency behind trying to bring them into the Church, when we should be focused on converting the pagans, the atheists, the total unbelievers?
I believe that this is one of those things where Jesus would say "[The one thing] you should have done, without leaving the other undone." It's true that the unbaptized and the non-Christians are in more grave danger, and therefore are a top priority. But that doesn't mean that bringing fellow Christians fully into the Church is not also a high priority. We must learn, as the saying goes, "to walk and chew gum at the same time."
But why should we consider it urgent that people become Catholic if they are already Christian? If we're not gravely concerned that they may be going to hell, then why does it matter? I'm glad you asked. Because I can think of many reasons.
1. Because Christ Prayed for Unity: Christ's longest prayer recorded in Scripture includes a prayer that all His Followers be one. In fact, He prayed to the Father "that they may be one, as We are one [emphasis mine]." I have heard it argued, from more than one source, that this is a reason we shouldn't care about converting non-Catholic Christians. The argument goes that this will only cause tension and useless argument over Catholic-specific dogmas, which wound our unity. While it might be ideal for all to become Catholic, we should settle for a "lesser unity." However, Jesus' prayer does not lend itself to this. He prayed for a oneness so profound it mirrored that of Himself and the Father. Now when it comes to Truth, I ask the following question: Is there any dissent or disagreement within the Holy Trinity? Of course not. So it's also true that we should long--as passionately as Jesus did--for all Christians to be so unified that there is no disagreement in matters of morality or doctrine. This cannot come about by "agreeing to disagree," but can only happen when all Christians agree on these matters. Perhaps we'd like to look at another reason that agreement among Christians is so important...
2. Because the Things about which we Disagree are not Trivial: As it stands, there are some very stark disagreements about even some serious doctrines and moral questions: "Is communion symbolic or is Christ really present?" "Is baptism necessary?" "Is X--say, using birth control--a sin?" "Are we obligated to do Y--such as attend Mass every Sunday?" "Is there one true Church?" "Is it okay to pray to saints?" "Is confession with a priest necessary?" and a host of other questions are all questions that each can only have one answer, and whatever that answer is, Christians should be concerned that we all find it, not merely agree to disagree on it. Nor can it be argued that these aren't important. Example: If Christ really IS present in the flesh--and not merely the spirit--in communion, then we OWE Him our worship in that form as well as any other, but if He is NOT present, and the bread and wine do not become His Real Flesh and Blood, it would be IDOLATRY to worship mere food. Only by knowing the answer to this question--if only by faith--can we determine whether we're committing a grave sin (culpably or otherwise) one way or the other. There is no in-between. The same is true on many of the other things about which Christians disagree. They simply aren't frequently trivial. That's not to say that those who "get it wrong" to no fault of their own will go to Hell, but it is to say that these things are important, and so it's much better to agree on them than to merely "agree to disagree."
3. Because Evangelizing is about Now, not only about Heaven: Some may say, "As long as they've got enough to get to Heaven, why should we strain over whether or not they convert?" If one has that attitude, however, one might well ask "As long as that starving person is going to Heaven, why feed him?" Or "As long as the orphan is going to Heaven, why help him?" What a minimalist approach to working for the Kingdom! We were taught to pray, by Christ Himself, "Thy will be done on earth as it is in Heaven." Catholics do not have the luxury of thinking only Heaven matters. We are called to do our part in conforming this world as closely to God's will as possible, and not merely waiting for His will to be done in the next. That's why we try to alleviate suffering, where it is found, instead of simply dismissing it as temporary. That's why we help the less fortunate, instead of just leaving them destitute until they finally receive their Heavenly inheritance.
But if we are called to share our material blessings and enact justice in material matters, how much more urgent can it be to share the riches of our spiritual treasury, the Catholic Church, and spread the fullness of Truth--and thereby, pursue a more perfectly spiritually just society--far and wide? If we count the bodily needs of such high importance as we rightly do, we have absolutely no excuse to count the spreading of our full spiritual goods--Catholicism--as less. Sharing the wealth and bounty of the Church as fully as we possibly can with our other Christian brethren should be at least as important to us as feeding the hungry, clothing the naked, and visiting the sick and imprisoned, and we are called to do those things even for those who are "going to Heaven either way." We should take our duty of bringing people into Catholicism just as seriously.
4. Because there is Greater Strength in True Unity: We are called to transform the earth, to redeem our culture, as much as we can. Our current state of disunity makes this very difficult. But imagine the power that Christians would have if we were all united in one belief, one set of doctrines, one ethical code! We would truly be able to "set the world ablaze" with a transformation toward Christian values. If we truly believe in all that the Catholic Church teaches, however, then we know that this can only happen to the fullest extent if all are united under the Catholic banner. For example, from a Catholic perspective, one of the most rotten parts of our culture--that has had a grave impact on the "sexual revolution"--is its acceptance of contraceptives. Even the most conservative of our Protestant brothers and sisters generally accept contraceptives (although this wasn't true until less than a century ago), so this particular cancer on our society would never be solved by "agreeing to disagree."
This one's a tricky one, admittedly, because in our own culture Catholics are often more guilty than any Protestant of undermining Catholic values, culturally, politically, and otherwise. Catholics often support abortion and gay marriage, for example. But that's because there are plenty of baptized and confirmed Catholic who are more Protestant than Martin Luther himself. They "protest" against even those teachings of the Catholic Church that Luther would have accepted, and as a result they are not truly unified with us, neither in our Faith nor in our attempts to achieve a just society. But this doesn't mean we shouldn't try to bring non-Catholics into the Church, it just means that these dissident Catholics are just as in need of being evangelized.
5. Because Eternity is too Important to take Risks: The Catholic Church recognizes Protestants who are sincere in their faith as our brothers and sisters in Christ, and so should individual Catholics. However we must remember that the Catechism and Church do confirm that, objectively speaking, it is a sin to remain separated from (or hold beliefs contrary to) the Catholic Church. It's just that those who are so separated to no fault of their own are not held responsible for it. But there are two reasons that this is not a good reason to just "leave them to it" without trying to reach out to them. The first is that, similarly to number 3, helping others avoid doctrinal error and to know what is sin will enrich their lives in the here and now. The second is that we should never be complacent in assuming that every non-Catholic is "invincibly ignorant" and therefore safe (although I'm not saying we should assume the opposite either; we shouldn't assume either way). What about, for example, someone who sort of suspects Catholicism might be true, but who is willfully refusing to consider it because it would upset his life too much, or otherwise be too difficult?
I speak from experience: That was once me, for at least a year before I decided to join the Church. I had begun to realize on some level that Catholicism might not only be a fellow Christian Church (which I'd always believed) but may in fact be the true Church, but I was too afraid that such beliefs as "Only one true Church" might make my Protestant loved ones and friends think I was a snob. Had you asked me, during that year, if I "secretly knew" that Catholicism might be true, I would have denied it, because I denied it to myself--so strong was my desire to believe that Catholicism was just one church among many, so that I didn't have to make such a tough choice. I held back because of fear, not because I was "invincibly ignorant." And, because of that, I am not confident in what would have become of me had I died.
Before you decide I'm being too hard on myself, consider this: What if it had been some other sin, besides schism? What if I'd been raised to believe it was okay to live a gay lifestyle, had been taught the "alternate" interpretations of Scripture that some trot out to allow that? What if, at some point, I'd begun to suspect that it might be a sin to live a gay lifestyle, but went into denial because it might upset all my gay friends, although I did continue to maintain a devout prayer life and observe all the other commands of Jesus? Objectively speaking, both schism and living a homosexual life are sins, if Catholicism is true. So there is no reason to believe that it would have been okay for me to continue living in schism when some part of me, deeply buried, "knew better," if we do not apply that same excuse to my living in the gay lifestyle in this hypothetical scenario--and I think most orthodox Catholics (and indeed devout Bible-believing Protestants) would feel uncomfortable risking giving someone a false sense of security in the hypothetical scenario. For a Catholic, then, it should be no different with schism. If not for the tireless work of apologists for Catholicism, people who had a passion for bringing other Christians into the Church, then I might never have had enough information nor seen enough conviction from Catholics to "tip the scales" and make me give up my denial. So we should all endeavor to do our part in helping others who may, for all we know, be in the same boat I was in.
I'm not talking about brow beating people, or approaching people with a smug attitude of superiority that suggests we think we are "better" than they are. That would have probably chased me away from Catholicism very quickly, because among other flaws I have too much pride to have ever admitted defeat if someone had made it into a war. It's wise and right that the Church recognizes that there is good in other denominations, and the use of "ecumenism" is precisely in fostering the kind of mutual respect in which hearts can be open to what we have to say. Only in humility and graciousness can we hope to reach those who stand where I stood shortly before my conversion. But there must be firm conviction, it must be possible for those around us to see that we are Catholic not because it's just a really good "denomination," but because we believe this is the True Church. No one is going to be drawn to our Faith, at least not for the right reasons, if they get the sense that we think our doctrines and specific beliefs are "incidental" or "not important." And combined with our conviction, we must be as prepared as possible to explain to others why we believe as we do.
In Conclusion, I want to reaffirm that it's noble and good to accept Protestants as our brothers and sisters in Christ. Some of the most faithful Christians I know--certainly when it comes to loving Christ and having the best of intentions--have been Protestants, some in my very own family. Many Protestants, on that level, are more worthy of respect than many Catholics, and certainly more than I myself. This isn't about disrespecting Protestants or saying they are "less Christian." It is about wanting to share the fullness of our Faith's riches, precisely because all those who have been baptized in Christ have a right to this Treasury, and by His Grace deserve nothing less. So in fact the more virtuous and in love with Christ a Protestant is, the more it is his birthright to become a Catholic. We owe it to God to proclaim His full Truth, not only the parts that "all Christians agree upon." And we owe it to our separated brethren to give them a real fighting chance to join the One True Church, and experience the richness that dwells here.
NOTE: The article The Whole House from the New Oxford Review is a great piece on this same topic. I highly recommend it. The link, unfortunately, won't allow you to read the whole article though.