By Susanne Gargiulo, Special to CNN

As pumpkins, witches and faux cobwebs have taken over much of North America for Halloween, Clare Slaney-Davis is preparing an October 31 feast that some would consider much spookier, with table settings for her grandparents, a great-aunt and other relatives who have passed away.

As she and her living guests eat, they'll share stories and memories of loved ones they've lost.

The Christian debate over Halloween

Slaney-Davis, who is based in London, isn't preparing the feast for Halloween. Instead, she and pagans around the world are celebrating Samhain, the beginning of the pagan new year, a night when the veil between the worlds of the living and the dead is believed to be the thinnest of any time during the year.

That's why it's a night devoted to ancestors. "We honor them, and we recognize that we don't live in a world of people who are merely dead or alive," says Slaney-Davis, 46. "Ancestors are central to us."

Along with the Catholic holiday All Saints' Day, Samhain is considered an ancient forerunner of Halloween. Samhain began as a Celtic celebration marking the end of harvest and the beginning of winter's hardship.

Today, pagans play down the Halloween-Samhain connection. But the growing popularity of the pagan new year in Europe and North America is part of what many experts say is a global revival of paganism.

Slaney-Davis, who trained as a witch and a druid, says her religion has nothing to do with ghosts and ghouls. "To me, being a pagan means being in divine balance with nature and being responsible for my actions," she says. "I understand that my behavior has an effect on people I don't even know exist. It is not a theology of perfection but one of belonging."

Over-the-top jack-o'-lanterns

But it is a theology that's gaining ground. According to the 2008 American Religious Identification Survey, the number of members of "other religions" or "new religious movements," categories that include pagans, more than doubled between 1990 and 2008, to 2.8 million.

The survey, conducted byTrinity College in Connecticut, reported that the numbers of Wiccans and neo-pagans had also doubled in that time.

Contemporary pagan religions like Wicca and druidism are considered neo-pagan movements.

"(Paganism) is one of the fastest growing religions in the world," says Michael York, a retired religious scholar from Bath Spa University in the UK. "True numbers are impossible to come by because many people are wary to admit they are pagan, and reliable statistics just don't exist."

Movies that scare the people who scare us

While paganism covers a range of individual religious groups, including Wicca, druidism, and shamanism, they're bound by some common denominators, such as roots in ancient, pre-Christian beliefs, and their view of nature and the whole physical world as sacred.

"In traditional religions you have a conflict between God and nature," says York. "But for pagans, nature becomes the truest expression of the divine."

That, he says, is a big reason why paganism is seeing a revival: "If nothing else, because of the impending destruction of our environment, and our focus on finding a way to live in balance with nature."

Another key pagan belief is the freedom for each person to determine his or her own way to and view of the divine. "Paganism doesn't put restrictions on what you can and cannot believe," says Jason Pitzl-Waters, co-founder of the Pagan Newswire Collective and the pagan blog The Wild Hunt. "It grows out of an ethos that there isn't just one sacred way to understand the world."

But that lack of dogma has become something of a stumbling block for the movement. "Because paganism is very individual, it creates the problem of not having a unified voice, because nobody speaks for the movement as a whole," says York.

Another problem pagans face is one of image: For centuries, including during the Roman Catholic inquisition, pagans were denounced as heretics and devil-worshippers.

"One of our greatest challenges is to overcome the hostility of groups that still see us as evil," says Pitzl-Waters. "To some conservative Christian groups, we are an early warning sign of societal collapse."

Just last week, an opinion column in The Christian Post, an online newspaper, warned that the "dark festival" of Samhain is an invitation to the devil. The column said that "even though you don't consciously call upon Satan, his demons are nevertheless present any time a Wiccan goes through a spiritual door by using magic." It calls on Wiccans to ask forgiveness for their sins and to turn to Jesus.

"Part of what is scary for conservative religions is that as a pagan, I consider myself part of the divine," says Holli S. Emore, executive director at South Carolina's Cherry Hill Seminary, which has one of the world's first graduate-level programs for pagan ministry. "That means God lives in me, and that is blasphemous to some. To me, it's a big responsibility to do good and act right."

Scholars say that the neo-pagan view of God being everywhere and in everything is not a foreign idea on the global religious stage. "Much of modern paganism looks to older religions like Shinto, Hinduism and indigenous religions, which see spirit in everything," says Jenny Blain, senior lecturer in sociology at Sheffield Hallam University in England and author of several books on paganism.

"If you add all those to modern paganism, that is a considerable part of the world that does not live with traditional Abrahamic views," she says.

There are signs that paganism is gaining some acceptance in the nonpagan world. For the first time last year, the government of Britain recognized druidism, an ancient pagan belief system, as a religion.

"People either see paganism as dangerous or as a joke," says Pitzl-Waters. "But it is a serious global movement. Paganism has arrived as a world religion. It's not just a bunch of counterculture types playing witchcraft games."

That said, traditional witchcraft rituals, like gathering in circles and uttering spells, have an important place in modern paganism, which further unsettles more traditional religious believers.

"Because Christianity is more conservative, anything seen as supernatural or magic automatically becomes of the devil," says York. "Because of that dichotomy, paganism is automatically seen as satanic."

"People fear what they don't understand," says Emore. "But spells are basically prayers with props. What we call magic is the intentional use of power to achieve change, and just like with prayer, what you are doing is tapping into an inner resource. Gathering in a circle and acknowledging the four elements is nothing new - this is something Native Americans and many ancient nature-based religious people did as well."

For neo-pagans, the four elements - earth, air, water and fire - are closely linked to their view of a sacred planet. "The attributes associated with each element become tools in our meditation and in practices such as spells," says Emore. "Water is associated with emotions and intuition, air with intellect and communications, earth with foundation and stability, and fire with passion and action."

To York, paganism's ancient rituals also help bring a sense of enchantment back into life.

"The ancients had a sense of the magical, but with Christianity came a diminishment," he says. "The magical was denied, everything became inanimate, and from a pagan perspective we lost our connection with the sacred. I think we are rediscovering that now."

"Pagans understand there comes a winter, which is a time to ready for rebirth," York says. "For us, the last 2000 years has been the pagan winter."