In a recent posting on Patheos, Star Foster speculated on whether or not Wicca is a Christian heresy. A number of commenters disputed her claim: most agreed with Erynn Rowen Laurie that: "[Wicca] doesn't position itself as Christian in the same way that, say, Mormonism does." I tend to agree. Wicca does not attempt to redefine Christian Scriptures in the way Christianity redefined Judaism's holy books as the Old Testament and Islam redefined Christianity's "New Testament" as the Injil. Nor have they redefined the holy figures of Christianity, save insofar as they might incorporate any other mythical being into their practices. In fact, most American Pagans at least run screaming from anything which might suggest "Christian corruption." Only recently have Pagans begun exploring Psalm magic, petitions to the Saints, and other practices which have long been part of traditional folk witchcraft.
Instead, I might argue that what many modern Neopagans have done is the opposite of heresy. Heretics seek to cull away the detritus and distractions which have accrued upon the True Faith. They do not reject their natal religion: rather, they seek to save it from those who have led it astray. To that end, they reject the innovations and missteps which they see as corruptions. Compare and contrast this with the Neopagans who begin their journey into the faith by rejecting the Church altogether. They see Wicca and Goddess Religions not as the perfection of the Christian faith but as its antidote.
Yet, paradoxically, this often means that they preserve more of the original orthodox belief structure. The heretic must carefully pick and choose what parts of the True Faith come from the original and which parts are deviations. No such caution is required by someone who wants to jettison the whole structure and start anew. They see their rejection as an end in itself: all they need do is remove those elements which are obnoxiously and obviously "Christian." And so they rebuild a faith which contains no crosses or Messiahs - but which is redolent of many other Nazarene ideas and preconceptions.
I've spoken in the past about the Neopagan interest in Holy Writ. Snorri Sturlsson identified as a Christian and compiled the Elder Edda stories as a political rather than religious act: Ovid wrote his Metamorphoses to entertain patrons, not honor the Gods. And yet many Neopagans seek to determine the validity of spiritual experiences by comparing and contrasting them to these and other ancient works of fiction. There are, of course, many religions which get along just fine without Sacred Scriptures, relying instead on amorphous collections of myths and tales. (see Ocha'ni Lele's collections of Patakis for one excellent example). But this model is often neglected in the quest for a guidebook: the Lore said it, I believe it, and that settles it.
Then we have the "Threefold Law" and the idea that bad deeds bring "bad karma" while noble behavior reaps "good karma." In Vedic Hinduism and Buddhism "good karma" is like "good cancer" -- karma is that which entangles us in this world and keeps us strapped to the Wheel of Rebirth. Yet in the West Gautama's wisdom has been conflated with the prosperity Gospel which states that God rewards the virtuous and punishes the wicked in this lifetime as well as the next. The idea that actions have consequences is certainly not unique to Christianity: many faiths believe, for example, that violating spiritual taboos can be devastating to one's health and well-being. But I would argue the self-righteous outrage of the Karma Kops and Threefold Lawyers has more in common with their hated Fundie preachers than with the spiritual practices of pre-Christian Europe.
In its early days, Christianity incorporated all kinds of myths and spiritual heroes into its practices, then re-interpreted them for a Christ-loving audience. Local gods and heroes were recast as saints working within a Christian paradigm in the service of the One God. Compare and contrast this with efforts to mix and match various gods and pantheons into a "Horned God/Mother Goddess" model. Instead of accepting these gods and their stories as a truth in themselves, they are reduced to a signpost which points the way to a Greater Truth.
And finally we have what may be the most insidious of preconceptions: the Manichean battles between Good and Evil. Many Neopagans are happy to tell you that there is no Satan in Wicca - then yammer on at length about the horrors of Christianity and how the Evil Christians destroyed the peace-loving matriarchal Goddess-Worshippers. They never stop to think how their claims echo tales of Christian warfare with powers and principalities, how their slain witch-queens play the role of Christian martyrs, or how they have exchanged the TV evangelist's polyester suit for a tie-dyed pentagram T-shirt.
Luckily, this situation is not hopeless. Earlier I asked for non-Christian examples of evangelism and martyrdom: in response, Sannion at House of Vines provided a lengthy list of Dionysian priests and priestesses who had spread His fame and even given their lives for His cause. Imagine an ecstatic faith based not on Christian models but on the Bacchanalia, one fueled by passionate believers who were willing to die for Dionysos and who wanted to set the world aflame with His passion. This is the kind of revival we could see - indeed, which we must see - when we strive to reach beyond mimicking Pagan ways of worshipping and strive instead for Pagan ways of seeing, living and being.