Did you know that we celebrate Christ's birth on December 25 because Pope Julius I wanted to substitute Christmas for the Pagan holiday celebrated that time of year? There are several Pagan holidays around the winter solstice from which Christmas is a collection of traditions. Caroling, feasting, mistletoe, yule logs, hollyberries, evergreen trees and gift-giving are all Pagan holiday traditions. Even Santa Claus, whom I believe has a basis in Saint Nicholas, is also based in paganism, along with his reindeer.
"Easter" isn't even a Christian name for a Pagan holiday; it's a Pagan name! Easter is known by many other names as well, including the titles of goddess of licentiousness, goddess of love, and goddess of fertility. The bunny is a Pagan symbol of fertility, and the eggs have several origins, none in the least bit Christian. Lent is also Pagan, giving up something for 40 days to mourn the death of Tammuz.
See this article for more interesting information on Christmas, Easter and other non-Christian holidays with decidedly Pagan backgrounds. I don't completely agree (and naturally, don't take this as your only information! Look it up and research further for yourself!) with everything they say, but it is very informative and a good overview of all the commonly celebrated holidays. (By the way, my family has never celebrated Halloween. I always thought that should be obvious; there isn't even a hint of any Christian excuse for that pagan holiday!)
When I first heard of Santa Claus from one of my friends, I remember thinking it was the silliest thing I'd ever heard, and I flat-out told her that there couldn't be any such thing. When I told my parents about it that night, they told me about Santa Claus, the Easter bunny and the tooth fairy and how parents usually lie to their children about the existence of these creatures because it's "fun." Then they explained that they didn't want to lie to us and later have us go through the possibly painful experience of "growing out" of those lies. Strangely enough, we also never feared the typical "monster" under our beds or in our closets.
As I grew older, the idea of parents lying to their young, innocent, trusting children became even more repugnant to me. I could understand non-Christian parents thinking they were doing something fun for their child, but Christian parents, desiring to raise their children to be Godly, should realize what a horrible thing they are doing: lying, which later might destroy their child's trust, and possibly also causing the child to view Jesus somewhere on the same level as these fantasies! After all, if Santa and the Easter bunny know when you've been bad or good and the tooth fairy knows when you've lost a tooth, they must have almost the same powers as Jesus, because Jesus knows all that too. And then, I wonder, which figure will the child admire the most? The ones that bring him toys, candy and other goodies, the one who leaves him money for a natural consequence of growth or the One that died for his sins?
I don't feel that I missed out on anything by growing up without believing in these fantasies. I've always been extremely grateful that my parents never lied to me about anything (so far as I know) and that I can always trust them to be honest, because they value my trust in the them over my "fun."
I know it is enjoyable to celebrate these holidays, especially because they are mostly accepted in our culture as "Christian" holidays. But truly, we don't need holidays to celebrate and rejoice in our relationship with our Lord and God. At the last supper, Jesus said, "Do this in remembrance of me." Taking communion, baptisms, prayer meetings and singing worship songs can be done any day of the week, and are all beautiful reminders and celebrations of Jesus and what He has done for us. And that's all without Pagan traditions.