I don't practice Wicca, but do believe and practice witchcraft. They aren't exactly the same thing, and I can't explain Wicca the way I can witchcraft as it relates to Christianity.
First, let me say witchcraft isn't a religion. It's a way to worship and live. Wicca is a religion with it's own set of rules and beliefs. I'm a Christian witch. I believe Jesus was God's son. I believe He was crucified and buried and on the third day rose from the dead. I also believe in the virgin birth. I believe, though, that God isn't just a "father" -- not just a male. There has to be a female as well for us all to be made in the image of God.
Now for my other shocking statement: Jesus was a witch. I completely believe that. Well, if He were around today, that's what He would be, anyway! He preformed miracles. He believed — and preached — that everyone had the power and ability to preform those miracles. He believed God was present in nature. He commanded the weather, and formed a relationship with the elements. He could channel spirits and talk with the dead. He foretold the future. And Christians are to live like Him, right?
Does that help? Or did I just raise more questions for you? If so, please ask and I'll do my best to explain where I'm coming from and what I believe.