Except against the tribesman of course.
Is it his fault he was born and lived with no knowledge of Christ?
What may not seem obvious given the way many Christians speak on such things is that there are many, many issues which there simply does not exist an "official" Christian perspective. When we look through the history of the Christian Church we can see all sorts of theological questions being raised, argued, discussed, and with more definitive conclusions--such as the Incarnation which was, in many ways, the central topic of all seven of the ancient ecumenical councils.
But then there are topics of theological speculation that simply don't have a definitive answer, there has never been a definitive historic consensus; different Christian groups may have positions one way or the other, but in terms of what we might call the consensus of the faithful there is no "the answer".
The topic of hell is precisely one of those issues. There has never existed a definitive, orthodox affirmation on the issue of "hell". Likewise the consensus of the faithful over a question such as "what of those who have never heard the Gospel" has no answer; it exists in the realm of faith and hope. The faith is in the God who makes Himself known in the Person of Jesus who offers Himself for the whole world, the hope is that the salvation of everyone is in the hands of this God--and therefore His judgment and mercy shall, indeed, be truly righteous.
I would further want to expand on what is meant by "judgment" here, the idea of "judgment" frequently has very specific connotations in many people's minds--judging criminals as guilty and sentencing them for punishment; but that's not what judgment is or means. Judgment, in the biblical sense, involves justice or righteousness--the act of setting or making things right. An example might be a widow whose rights have been taken away or violated by another, a wealthy person taking away a widow's property rights; she would therefore go to court to make her appeal, and the court's judgment to restore her rights and property would be, indeed, judgment, righteousness. This is the reason why, frequently, in the Psalms and the Prophets the writers speak of God's coming judgment as something to be
celebrated. Because when God judges He, being good, merciful, and just, will make things right; He will restore what is lost, He will mend what is broken, He will heal what is ill.
The Judgment of and Justice of God is first and foremost always about God making things right. In the New Testament that judgment and justice is understood through the death and resurrection of Jesus whereby God is bringing about new creation, bringing restoration to the world, that includes forgiveness of sin. In forgiving sinners, in justifying and sanctifying sinners, this is God judging and judging justly.
So when we talk about people in the light of Christ, His death, resurrection, ascension, and coming again we are talking about the God of new creation--this is the good God of righteous judgment setting things right; the New Testament describes what that looks like for the people of God, the baptized; and the the stark reality of what existence outside of this setting-things-right looks like (at least in small degrees); but there is no wholly all-comprehensive picture offered. The present state of things is falling away as God brings renewal and restoration to the world and there will be those who will insist on being part of that which is falling and fading away--but the ultimate vision in the Bible isn't so much a black and white good guys and bad guys rewards and punishments that we typically envision. Instead the ultimate vision in the Bible is the total restoration of all things, of all creation, heaven and earth; and the coming together of heaven and earth as the heavenly city is brought down, and we read that in the middle of the city is the tree of life affixed on both sides of a river "whose leaves are for the healing of the nations".
The ultimate vision of the Bible is healing, renewal, restoration. It is the vision of hope.
So where does the hypothetical tribesman fit into this narrative? He's there in the vision of hope--however and whatever, in the end, that truly looks like.
-CryptoLutheran