If these men were able to carry out such a hoax, then they themselves deserve to be worshiped as gods.
It is an interesting point, I think, about Christianity and the "fall" of nations. Indeed, Augustine addresses this point in "The City of God" sometime after 410 after the sacking of Rome. I myself do think that the adoption of Christianity by a nation will cause a "fall" -- but that such is really a longer-term incubation and transformation. If Saudi Arabia, for instance, were to become Christian at a grass-roots level, assuredly, this would cause the downfall of the current system. I would guess that there are too many incompatibilities for the current Islamic system to remain intact if such a change were to occur, although I could be wrong about this.
In Europe, we see mighty Rome succumb to the barbarian invasions in the West, and largely remain silent for centuries. But what do we see when Europe again awakens? A flourishing and well-ordered civilization of rights and responsibilities that extends well beyond Imperial Rome's original sway, where a scholar from England could be welcomed from Germany to Spain and beyond. A civilization where slavery has quietly ceased to exist, and where the life span of women begins to extend beyond that of men. A land where -- in one country alone and in one century (France) -- more stone was moved in building the great cathedrals than was done by Egypt in its entire history of pyramid building.
It was a great and long period of incubation as Christianity absorbed the barbarian peoples of Europe and transformed them -- rather than killing them or putting them on reservations. By the end of the Middle Ages, the scientific method can finally spring free and develop, whereas in other cultures the development of science always failed because of cyclic notions of causality or an indistinct notion between Creator and creature.
But with that being said, I do think that the adoption of Christianity can be "bad" in the short-run. God is not specifically a Norwegian, for instance, and what is good for the Vikings in the short-run may not be good for themselves or humanity in the longer-term. In Mexico, the adoption of Christianity by the natives certainly was a cause in the fall of that empire.
For some of these reasons, I am not a White nationalist as are many on this forum. I do think that Christianity does pose an inherent "vulnerability" for those who are already adherents, but that this vulnerability is necessary for a spreading beyond the original circles and for making the cultures of humanity stronger and better in the long-run. I would consider that an important priority of a government in a Christian society would be to allow some interaction between its own people and foreign peoples, but to carefully regulate these movements and migrations so as not to cause a weakening of the fabric of the society. It is not an easy task, and many empires throughout history have not been able to accomplish this task successfully.
As for the Norse and Greek mythologies, I think at least some of these are remarkable in preserving ancient truths. I cannot speak of all of the mythologies, but some of these I am quite certain are simply a case of having retained the symbology, but the language having changed and so the story becomes garbled and superficially outlandish. Uncover the original language, and then you will understand the ancient truths. I would argue that these mythologies, in fact, are partially what made the European mind accept Christianity more readily than other peoples. The European languages, I think, were closer to the language from which the original mythologies were based, and so they more easily understood the fulfillment of the ancient prophecies. It was not only the ancient Hebrews who had prophecies awaiting fulfillment, but it was also the astrologers.