The idea that God is the very ground of being is itself a belief system. For that matter, would a just God condemn someone for not believing in God when that one was never given a chance to believe.
I think most non fundamentalist Christians would agree with Wesley on this point:
“It cannot be doubted, but this plea [lack of knowledge] will avail for millions of modern Heathens. Inasmuch as to them little is given, of them little will be required. As to the ancient Heathens, millions of them, likewise were savages. No more therefore will be expected of them, than the living up to the light they had. But many of them, especially in the civilized nations, we have great reason to hope, although they lived among Heathens, yet were quite of another spirit; being taught of God, by His inward voice, all the essentials of true religion. Yea, and so was that Mahometan, and Arabian, who, a century or two ago, wrote the Life of Hai Ebn Yokdan. The story seems to be feigned; but it contains all the principles of pure religion and undefiled.”
“Yet it is not our part to pass sentence upon them, but to leave them to their own Master.”
“Perhaps there may be some well-meaning persons who carry this farther still; who aver, that whatever change is wrought in men, whether in their hearts or lives, yet if they have not clear views of those capital doctrines, the fall of man, justification by faith, and of the atonement made by the death of Christ, and of his righteousness transferred to them, they can have no benefit from his death. I dare in no wise affirm this. Indeed I do not believe it. I believe the merciful God regards the lives and tempers of men more than their ideas. I believe he respects the goodness of the heart rather than the clearness of the head; and that if the heart of a man be filled (by the grace of God, and the power of his Spirit) with the humble, gentle, patient love of God and man, God will not cast him into everlasting fire prepared for the devil and his angels because his ideas are not clear, or because his conceptions are confused. Without holiness, I own, ‘no man shall see the Lord;’ but I dare not add, ‘or clear ideas.’”
The idea of a baptized heathen is a fairly traditional doctrine in Christendom, and it is, to my knowledge, predominantly Lutherans and Calvinists who are hostile to any notion of anonymous Christians.
