Skinwalker, Christianity was, by no means, dead in Britain despite what the neopagans and neoWiccans would have us believe. There was a very active and thriving Christian Church in Britain until it was destroyed by the Anglo-Saxon invaders. The British Church gave birth to Saint Patrick, despite that recent tv show to the contrary. The Celtic Church of Ireland and of Scotland that was stamped out by the Roman Catholic Church of the Norman invaders of those countries was the direct descendent of this original British Christian Church. When the Romans left, yes, they took with them the imprimatur of state authority which the Church had used since the days of Constantine I about 100 years before, but Christianity did not die out, it only became the majority, but shrinking, religion up into the period of the Saxon invasions. The loss of state support meant, of course, that the other religions that had gone into hiding could and did now reappear, especially the old Celtic religion. But, you know, it never really disappeared. Bridgid, the threefold female Celtic Goddess; Maiden, Woman in Full Bloom, and Crone became St. Bridget or St. Bride or whatever and many of the springs that were sacred to the Celtic gods were the, by some magic, converted into sacred shrines for a multitude of Saints. Wonderful, no? Christianity is a most eclectic religion just as the Romans were a most eclectic people, quite willing to adopt anything of use from anybody.
When Augustine of Canterbury showed up in England to convert the anglo-Saxons, he found that there was already a thriving Christian Community in the north and west of the island and over in Ireland that paid no allegiance to Rome, but operated on its own. This was the Celtic Church of Sts. Patrick and Columba, and it had been making headway with converting the Anglo-Saxons, but slowly. Augustine had much greater success, starting 596 CE. The two versions collided in the Saxon kingdom of Northumbria at the Synod of Whitby in 664 CE, when the two Churches presented their cases to the Northumbrian king, Oswy. After some debate and consideration, he chose to follow Rome, and that eventually led to the end of the Celtic Church. See
http://www.newadvent.org/cathen/15610a.htm for more details if you wish.
BTW, are you aware of the connotation of the name "Skinwalker" in Navajo culture? It is not one that I would care to own.
