Well, I was reading about Druids and Christianity. I had assumed that the Christians had forced their religion upon the Druids in the same manner as when Theodosius made it illegal not to be a Christian in the Roman Empire in the year 392, or when Charlemagne waged war to covert the Saxons in the 8th Century, or when the Spanish Inquisition forced Jews, Muslims, and others to convert. With the Druids, it was apparently a relatively peaceful coexistence. In fact, the Saint Columba said, “My Druid is Christ.” Some say that Druidism was already in decline by the time Saint Columba began preaching to the Irish pagans. Others say it was because Columba chose follow something Jesus said, “Let your light so shine before men, that they may see your good works, and glorify your Father which is in heaven.”
Ironically (or sadly typical, really), Saint Columba did not get along with some of his fellow Christians as well as he did with the Druids. In the year 561, Columba got into an argument with his former teacher, Finian. As explained at OpenSource.com:
Columba was known for constant study and prayer–really, really constant. He is said to have written 300 books, by hand of course, continuing to transcribe up to the night before he died. Finian and Columba got into a disagreement over a psalter . . . Columba borrowed the manuscript from Finian–possibly without permission–and secretly copied it with the intention of keeping it for his own use. But Finian said no, that this was theft–illegal copying! He demanded that Columba hand over the copy he had made. Finian took the matter to King Diarmait mac Cerbhiall, the High King of Ireland, for arbitration . . . the king ruled in Finian’s favor, famously saying, “To every cow belongs its calf; to every book its copy.” In other words, every copy of a book belonged to the owner of the original book . . . the story didn’t end there. After more arguing and Columba’s next offense (harboring a fugitive from Diarmait), the result was the Battle of Cúl Dreimhne, the death of 3,000 people, and Columba’s exile . . . Ray Corrigan wrote a very interesting version of the story (PDF) in a paper for Gikii in 2007 if you’d like to read more.
Maybe that’s why the Druids liked Columba. On one hand, we have Druids practicing human sacrifice, and on the other hand, Christians warring against each other. The place must have been a madhouse.