Healendry, Germanic Christianity, or Viking Christianity, are all names that broadly call on the same frame of beliefs which began in the Iron Age, otherwise named the "Dark Ages", or "Viking Age", which was the time when Christian belief was spreading throughout the Northern Tribes of Europe and being taught to our predecessors. The Germanics of the Iron Age were widely baptized and intaken into the Church, seeing the Truth of the Lord and becoming among the most heartfelt in all of Christendom.
A token of the fervor towards Christ felt by the Germanics is a saying that is bound to the Hallowed Warden of the Fellowship of Germanic Christians, King Clovis I. Named "The Most Christian King", when he was being taught the tales and laws of Christianity, the Priest began to teach him about the Passion and the suffering of Christ at Calvary, whereupon Clovis clutched his axe, stood and shouted, "If I had been there with my Franks, I would have revenged his wrongs!"
This same soul and true love for Christ was felt throughout the North, and our Germanic forefathers so called the Lord "Healend", meaning Saviour or Healer, and it is this name for the Lord which we find throughout the writings and sagas of Germanic Christians to tie the everlasting and almighty way of God into folkways with which they could understand God made flesh. It is this true love, and this bond to our folkways which drives the Fellowship to akindle Healendry.
In The Heliand, the Saga written by Saxons in the 9th Century which tells the Gospel through Germanic eyes, they refer to the Healend, "That Might-Wielding Lord", and His Thegns, the 12 Apostles, as a band surrounding Christ and toppling the rotting and misbegotten land which Judea and Galilee had become. This might used to overthrow rotting structures is found not only in the Gospel, but in the Tale of Northern Christendom itself. The Heathens, which had been led astray into worshipping false idols and their own ancestors, were put to an end by the light of God and His Church, whole Kingdoms came into the Water of Baptism, or fell like the rotten Oaks which they worshipped.
At the time The Heliand was written, Saxony was undergoing this very overthrow, as the Englishmen and Franks came to teach the Saxish folk about the Gospel and God, many powerhungry Kings wished not to bow to the King of Kings. An Englishman, by the name of Boniface, had preached to the Saxish, and when heading South of Saxony into Hessen, singlehandedly proved the Might of God over the Heathen idols by felling Thor's Oak, a tree which the Pagans had worshipped.
This led to the Christening of hundreds of Heathens, who witnessed firsthand the overpowering strength of God and His followers. Without doubt, this time of Hallows and Holiness swayed Germanic Christian understanding of God, and contributed to the fervency of their belief.