I’m glad this is turning into an interesting discussion! 😀
Ancient calendars and dates are absolutely fraught with difficulty. I’ve often heard the idea that the date for Christmas was chosen because it had been a pagan feast, Yule, the Roman Saturnalia and so on, however, there are some serious problems with this. Strangely enough, Christmas wasn’t such an important festivity in early Christianity and there were various conflicting dates for what would later become Christmas. The earliest mention of the December 25th date comes from the Donatists, a Christian group in 4th century CE North Africa, mentioned by Augustine of Hippo. Moreover, the feast of the Annunciation – the conception – was March 25th, the old Roman new year, nine months from March 25th and we arrive at December 25th and the March 25th date was also connected to the crucifixion because the conception and the crucifixion were supposed to have the same dates. Likewise Easter, Jesus was crucified at Passover, so for the dating of this we need to look at the traditions of Second Temple Judaism from the 6th century BCE to the 1st century CE. It’s all a far cry from Yule and Saturnalia and it’s certainly beginning to look more like a tradition with roots in the Middle East, North Africa and Judaism, which isn’t all that surprising all things considered. I don’t doubt that later on non-Biblical elements were incorporated into folk Christianity, but at the same time, as I said before, I wouldn’t read too much into things either.
Eostre is also problematic. We only have one ancient reference to her, in Bede, and no evidence of her cult. Now, we could take Bede on face value and accept that there was once an Anglo-Saxon goddess Eostre, but apart from that, there’s little else we know, Bede doesn’t describe in any detail her festivities or associate her with anything. The idea of associating the hare with Eostre originates with Jacob Grimm in 1835 and there’s not much to back it up really; furthermore, the traditional Easter hare seems to have originated with German Protestants. Another problem is that the sacred animal of the Germanic/Norse fertility and spring goddess Freyja was the cat, not the hare. As for Easter eggs, they seem to have originated in Persia and spread through what is now Iraq and Syria with Eastern Orthodox churches, thence into Greece and the rest of Europe. This appears to be a very ancient tradition, but there’s nothing all that historical to link it with ancient pagan Europe, at least not the Celtic and Germanic cultural areas. So, far from the church trying to stomp out pagan traditions, it seems that some of these pagan traditions were actually Christian in origin.
Unfortunately, starting in the 17th century, through the 19th century Romantic revival, the Celtic Twilight movement and then 20th century so-called “New Age”, there has been a lot of very poor scholarship, wild speculation and downright nonsense written about folklore, beliefs and traditions and perhaps Celtic spirituality has been in the frontline. Ronald Hutton is a good reference for clarity on many of these issues and more recent scholarship, better translations and more archaeological and historiographical work are improving things. Nevertheless, I always try to exercise a great deal of caution in a lot of the claims that are made.
Having said all that, each generation and society creates its own mythologies according to its spiritual and philosophical needs and things evolve and change.