Any religion must express some truths, or it will be utterly useless, and will gain no purchase among men. It will fail to convince them. They will see that it is just absurd.
So all perdurant religions express some truths. Nevertheless they disagree, or they would not differ. So none of them express the same set of truths. And to the extent that they disagree in any respect with Christianity about the Incarnation and its implications, they cannot but mislead men, to their spiritual detriment, and even in the limit to their damnation.
God has nevertheless told us that he is alone the way; so that, no matter how or where we go, we go by him. Thus all paths lead from him, are traversed by way of him, and lead to him. There is indeed then, despite their manifold irreconcilable disagreements, a transcendent unity of religions, as the Perennialists insist. For, you cannot do anything at all in disagreement with omnipotence; all you can do by way of disagreeing with him is disagree with your own being.
You may think you can contravene the Way of Heaven, but no; everything you do either expresses it, or fails to express anything at all. What you do may appear to blaspheme, but the blasphemy can really redound only to the blasphemer and his allies. If I say that God does not exist, I do not at all cheat God of existence, but rather work my own undoing, a bit. So if I blaspheme, I blaspheme only against myself. God is not mocked. He cannot be mocked, for he is invulnerable to our disagreements with him. How could it be otherwise, since he is infinitely potent?
He is on the other hand open always, and completely, to my agreements with him, and to my homecoming. How could it be otherwise, since he is infinitely potent? Infinite power just is infinite power to create, to redeem, to save and heal; these are all one power. How could any lesser power overcome it, or resist it, how divert or assist it? So all that we do, however errant, we do by virtue of him.
Everyone furthermore ends up willy nilly in the Throne Room of the Courts of Heaven, where all decisions whatsoever are ultimately understood and judged (and in virtue of whose judgements all subsidiary partial evaluations by creatures are enabled). There is no other place to end up. This is the meaning of ubiquity: not so much that Christ is in all places – although he is that, to be sure – as that all places are in Christ. As he is thus the Alpha of all things, so is he then their Omega and telos.
So everyone will end by testifying before the Throne. And as there is no guarantee of acquittal on the basis of a merely formal undertaking of agreement with the Lord of Heaven, but rather only by the actual satisfaction thereof, so in logic might a man who has never seen such a formality as either important or necessary find himself excused and admitted, as having done rightly what was possible to him under his circumstances.
Whatever the path one takes to the Throne Room, what matters is the real and total commitment of the decision for or against the King who sits there in judgement.
Every decision, of every man, no matter his circumstances, and no matter his cult insofar as he understands it, and no matter how trivial the matter of the choice, boils down to this: am I with him who is the most Real, and who is himself Reality? Or, not?
The experience of the Presence is Heavenly or Hellish, depending on the answer.