When I was a kid growing up in the Church of Christ in Dallas Texas I was always told you have to follow Jesus and be a Christian to be saved. That meant being baptized (which entailed total immersion in water) and it had to be in a Church of Christ, or you would go to hell. Even as a small child I would ask "what about the people born in China who never hear of the Church of Christ, would they go to hell? That issue alarmed me as early as I can remember. When that issue came up they would say "God is merciful he will take that into account." That's what we want ot hear. I still always wondered if it meant he would really let them off the hook. They weren't willing to thin it through to that extent. Still, when I went back to God and was born again at age3v23, after having been an atheist for about seven or eight years that seed was there and has formed the foundation if my adult apologetic and theological answer. Now the guys at the Secular Outpost have an argument (ala Jeff Lowder)  it's really against William Lane Craig,' in the comment section the troops are all enthused. They think they have a dynamite argument Christians can't answer. I think I did answer it but they just aren't listening. So I'm going to have to spell it out. The argument is not exactly about this issue but it does have a bearing. I think my answer to the issue also answers Lowder's argument.
The demographic aspects are not very prominent, they made more of a splash in the comment section. I still find it more logical to deal with that stuff first. The major part of the article is about are there sincere people who never accept Jesus but aren't resisting the Gospel. Of course most Christians say yes, believing there are not true atheists. Atheists of course claim otherwise and are offended by the idea that they are lying or self deluded. Before I deal with that it makes more sense to me to deal with the question "what happens to people who die never having had a chance to hear of Jesus?" I am going to do the wired thing and deal with that issue first then in part 2 deal with the main brunt of the article. Lowder mentions the possibility of isolated non Christians and their eternal fate as a final subpoint to his major point three in which he sights Schellberg:
The prima facie evidence of isolated nontheists. Schellenberg defines these individuals as “those who have never been in a position to resist God because they have never so much as had the idea of an all-knowing and all-powerful spiritual being who is separate from a created universe but related to it in love squarely before their minds–individuals who are entirely formed by, and unavoidably live their whole lives within, what must, if God exists, be a fundamentally misleading meaning system” (238). I wont quibble we know it's possible that some people have never heard of Jesus so te question is still valid. I find it hard to believe that anyone would not have heard of "God" in some sense. American atheist like to say that Buddhism is atheistic, it is not. Buddhists from Asia don't think that way. They don't have a "God" per se but they do have the Buddha mind which is much like Tillich's notion of the ground of Being (the Christian concept of God ala Platonic Christianity of the 5th century. Be That as it may I ill Just deal with the Gospel. Before getting on with thatI have a disclaimer. Nothing I say should be taken assaying that we don't need Jesus to be saved or that we can worship Krishna as Jesus or anything of that nature. I believe Jesus is Lord and if anyone is saved it's Jesus who saves them.
Having said that I don't believe that all people need to know it's Jesus who is saving them to be saved. Cyprian said there is no salvation outside the church, he said that in about 300A.S., hat they believe before that? There is nothing in the Hebrew scriptures to the effect that if you are not a Jew you are going to hell. Now it's true that the Bible lambasts the worship of idols but the OT had no concept of hell. This is widely known in most seminaries., Every thing translated as "hell" in OT is using the term "Sheol" meaning the grave. This explains Paul's words to the Greeks on Mars Hill (Acts 17--I'll get to it).
I have been assuming that experience of God is at a subliminal level. Since we all experience it that way we can experience it and not even know. Thus to talk about the inklings of ideas of God that we get and about any actual known experiences we have, we must filter that through cultural constructs. The reason is obvious, because culture is langue and it's through the constructs of culture that we interpret the world. God is beyond our understanding. Even those who experience God directly and so powerfully that they know it is real, are still confronted with a phenomenon of which they cannot speak directly. To make sense of it and to communicate it to others we must filter it through constructs. That means that our understanding of God is largely metaphor (at least our intellectual understanding).
Given this framework I've come to a slow conclusion over the last couple of decades that the same reality stands behind all faiths. That doesn't mean that I see Krishna or Bhudda as Jesus, but it does mean that I see God as the motivating instigator of religion as a whole and of belief in God in particular. I see God as working in all cultures. I see God as having interaction with all faiths, but not filling the blanks as other gods. I see a basis for this in the Bible.
To those who through persistance seek glory, honor and immortality he will give eternal life.But for those who are self-seeking and who reject the good and follow evil there will be wrath and anger...first for the Jew and then for the gentile; but glory honor and peace for everyone who does good. For God does not show favoritism. All who sin apart from the law will perish apart form the law and all who sin under the law will be judged by the law. For it is not those who hear the law who are righteous in God's sight, it is those who obey the law who will be declared righteous.Indeed when Gentiles who do not have the law, do by nature things required by the law, they are a law for themselves even though they do not have the law, since they show that the requirement of the law are written on their hearts, their consciences bearing witness and their hearts now accusing, now even defending them..." (Romans 2:7-15).
New American Standard and other translations say "their hearts accusing, now excusing them..." Most Christians are afraid of this conclusion and they down play this verse. Often Evangelicals will come back and say "he makes it clear in the next passage that no one can really follow the law on their hearts." Well, if they can't, than they can't. But if they can, and do, than God will excuse them. God knows the heart, we do not. The verse clearly opens the door to the possibility of salvation (although by Jesus) thorugh a de facto arrangement in which one is seeking the good without knowing the object one is seeking (Jesus). In other words, it is possible that people in other cultures who follow the moral law written on the heart know Jesus de facto even if they don't know him overtly. Paul backs up this conclusion in Acts 17:22-30  Paul goes to Athens as is asked by the Athenian philosophers to explain his ideas to them.
These were pagan followers of another religion. Paul stood up and said to them, "Men of Athens, I see that in every way you are very religious for as I walked around and observed your objects of worship I even found an alter with this inscription 'TO AN UNKOWN GOD' Now what you worship as something unknown I am going to proclaim to you."He basically says that they are worshiping God, they just don't know who he is. That's why he says "I will make it known to you." He doesn't say "you have the wrong idea completely." Most Evangelicals dismiss this as a neat rhetorical trick. But if we assume that Paul would not lie or distort his beliefs for the sake of cheap tricks, we must consider that he did not say "you are all a bunch of pagans and you are going to hell!" He essentially told them, "God is working in your culture, you do know God, but you don't know who God is. You seek him, without knowing the one you seek. He goes on,(v27)"God did this [created humanity and scattered them into different cultures] so that men would seek him and perhaps reach out and find him though he is not far form each one of us." This implies that God not only wants to work in other cultures, but that it is actually his paln to do things in this way. Perhaps through a diversity of insights we might come to know God better. Perhaps it means that through spreading the Gospel people would come to contemplate better the meaning of God's love.
In any case, it does mean that God is working in other cultures, and that God is in the hearts of all people drawing them to himself. Of their worship of idols, Paul said "in past times God overlooked such ignorance but now he commands all people everywhere to repent" (v30). Now what can this mean? God never overlooks idolatry or paganism, in the OT he's always commanding the Israelite to wipe them out and expressly forbidding idolatry. It means that on an individual basis when God judges the hearts of people, he looks at their desire to seek him, to seek the good. That their status as individuals in a pagan culture does not negate the good they have done, and their ignorance of idolotry does not discount their desire to seek the good or the truth. IT means that they are following Jesus if they live in the moral life, even though they follow him as something unknown to them. IT also means that all of us should come into the truth, we should seek to know God fully, and when we do that we find that it is Jesus all along.
One thing this might change is our understanding of the chruch. It was the theologian Cyprian (200-258) who said there is no salvation outside the chruch. This doctrine is called extra ecclesiam. He was born in Carthage around 200. He was made Bishop of Carthage in 248, died in 258. In his most important work, "De unitate ecclesiae." he states: "He can no longer have God for his Father who has not the Church for his mother; . . . he who gathereth elsewhere than in the Church scatters the Church of Christ" (vi.); "nor is there any other home to believers but the one Church" (ix.). Cyprian should not come across as a bad guy even though he makes this exclusivity statement. For one thing he favored reinstating (after suitable intervals of probation and penance) those who fell away under persecution recognizing the extreme hardship they were under. He also faced sickness in order to stay in the city and care for plague victims. He was falsely accused and put to death by the very church which he so ardently defended.
This is in the third century. Christianity had been going for a long time before this formal declaration that there is no salvation outside the chruch. Of course this doesn't mean they had not been saying it here and there all along. Yet they were pretty far removed from the understanding of Paul who way back there in the late 50s of the first century was telling the Greeks they already knew God but needed to know more about him. Not only had a lot happened, Christianity became a religion prosecuted religion of martyrdom, but also thoroughly gentile so that the perspective of Judaism was forgotten. Jews reject idols but they did not see pagans as damned merely for being who they were. Modern Jews still largely hold to that preservative.
One problem with extra ecclesiam is I'm a protestant! That began as a Catholic doctrine, when the split came with the east the Roman Catholics continued the idea, it's a Roman catholic notions. Though many protestants passionately accept the Father's as gospel the teachings of the Apostolic fathers became the teachings of the Catholics and are acted upon as though they exclude protestants. At least before Vatican II. While I am passionately defending extra ecclesiam a bunch of Catholics are looking at me and saying "but you are outside the church yourself!" So I have to re think this business of the nature of the church. First of all I have to see the church as the tool, not the point of the mission. It is Christ's mission not the church's mission. As Motlmann says "The Mission has a church." Meaning, the Gospel, being the light of the world, is the mission of Christ, the church is a tool belonging to that mission. I also no longer see the church as the agent of salvation. Christianity has tended to make the Church the point, and membership in it and Christ became a tool of the church.Membership in the church is not what saves us. It maybe valid, it may be necessary but it's not the saving agent. Christ's atoning sacrifice is what creates the ground upon which forgiveness is possible. The church just preaches the message.
Finally, the great commission ("go ye therefore into all the world and preach the Gospel, Baptizing everyone (or 'all nations')" that is not a command. It is not in the imperative. It really should be where you are going preach the gospel. It's not in the imperative mood so it's "go ye!" but "where you are going." More on all of this in comment section.
A poster in the comment section of Lowder's article says:
In addition to the excellent points made in the article, I think that there is very strong evidence against the Sincerity Denial Hypothesis in the form of facts about the distribution of non-belief, as well as from facts about human psychology (particularly, the fact that most people prefer not to be tortured forever).For example, belief in Christianity spread throughout the world in a way that is perfectly consistent with Naturalism but slightly baffling on Craig's views. There are no known Native American Christians prior to the arrival of European settlers. But on Craig's view the Native Americans MUST have been, on some level, willfully rejecting the belief in Christ, which one CANNOT do unless one is on some level aware that Christ is a thing that can be accepted or rejected.Of course that assumes conscious joining of the Church as a man made institution. If as Paul suggests anyone following the moral law upon the heart is seeking Christ defacto then there is no inconsistency. If as Paul says the Athenians guessed right that there is an unknown God they need to get to know then the spirits and great spirit of the native American points to the creator, then they weren't all necessarily lost nor where they all guilty of rejecting nor where they necessarily not following Christ without knowing it was Jesus they followed. All gods point to God! They are not all God but they point to God.
That same poster goes on:
Rival belief systems like Islam seem to correlate with certain areas in ways that suggest the surrounding culture was a significant contributing factor in the propagation of those beliefs. But on Craig's view one's rejection of Christ is entirely independent of one's culture, so it's a sheer coincidence that the really stubborn people who happen to find Islam more convincing, tend to be found in Islamic cultures. For whatever reason sincere believers all seem to live in the same places and those places are much less likely to be places where the dominant culture is Islamic and absolutely never places to which Christianity has yet to spread through naturalistic means at all.Christians don't live where Christianity has not spread, that's a tautology. But it's all over the world now. It's becoming major in China, Africa, and Japan. Did you know it's been in India since the Time of Christa? No the spread of Christianity is not not in line with what naturalism would predict. Naturalism would predict it would ie out shortly after the crucifixion of Jesus.
Additionally, Craig is committed to a fairly traditional conception of Hell and one in which a consequence of not accepting Jesus is eternal torment. Now, Lord knows there are some stubborn atheists out there but is it plausible to believe that not only all atheists but all non-Christians in the history of the world are so stubborn that they would prefer to be tortured in a lake of fire for eternity than believe something that Craig thinks is the most wonderful, life-changing thing that anyone can believe in?
That could cut both ays because it does not prove their denial is due purely to intellectual matters.
 Jeffery Jay Lowder, "WLC Denies That Anyone Has Ever Died a Sincere Seeker Without Finding God" Secular Out Post, January 2, 2016 (blog URL)
http://www.patheos.com/blogs/secularoutpost/2016/01/02/wlc-denies-that-anyone-has-ever-died-a-sincere-seeker-without-finding-god/ Accessed 1/10/16
 Jeff Lowde paraphrasing John Schellenberg (in his recent book The Wisdom to Doubt - See more at: http://www.patheos.com/blogs/secularoutpost/2016/01/02/wlc-denies-that-anyone-has-ever-died-a-sincere-seeker-without-finding-god/#sthash.h28GcHgr.dpuf
 Romans 2:6-14/Acts 17:22-30
 "Cyprian," Wikipedia, http://en.wikipedia.org/wiki/Cyprian accessed 5/13/14.
 James E. Keifer, "Cyprian of Carthage, Bishop and Martyr." Bibliographical sketches of Memorable Christians of the Past. Online source: http://justus.anglican.org/resources/bio/242.html
 Jurgen Motlmann, The Crucified God: The Cross of Christ As the Foundation of Criticism of Christian Theology. Fortress Press; 1st Fortress Press ed edition (September 1, 1993) 105.
Mission is rooted in the identity of God himself. God is on a mission, and Jesus is the embodiment of that mission. Jesus identifies himself as being sent more than forty times in the gospel of John. Then, near the end of the gospel of John, he says, ‘As the Father has sent me, I am sending you’ (John 20:21). The church is sent on mission by Jesus. It’s not that the church has a mission, but rather that the mission has a church. We join Jesus on his mission.