A little bit of history for those who see Halloween as some sort of "day for the Devil.".
Any "Goth" type or "devil worshipper" who tries to claim Halloween as "their" holiday is being rather presumptious, for the day itself did not grow out of evil practices. It grew out of the rituals of early Celts celebrating a new year and out of Medieval prayer rituals of Europeans.
In fact, the word "Halloween" itself actually has its origins in the....Church.
It comes from a corruption of the words "All Hallows Eve," which annually falls on October 31, because November 1 is "All Hollows Day" ("All Saints Day"), a Catholic day of observance in honor of saints.
The "scary" elements of Halloween don't come from the church, but rather, the Celts (yep, let's blame the Irish). In pre-Christian Ireland, summer officially ended on October 31, a day which featured a holiday called Samhain, the Celtic New year.
Legend has it that the Celts believed that on that day, the disembodied spirits of all those who had died throughout the preceding year would come back in search of living bodies to possess for the next year (the presumed sole hope for the afterlife).
Naturally, those still living didn't want to be possessed. So on the night of October 31, townspeople would do everything possible to scare away the spirits. They extinguished the fires in their homes, to make them cold and undesirable. They dressed up in all manner of ghoulish costumes. And they celebrated by noisily parading around the neighborhood, being as loud and freaky as possible in order to frighten away spirits looking for bodies to possess.
After the Romans invaded Ireland, they did their usual thing and cherry-picked certain local practices to make their own, which included Samhain. As time went on, that holiday was assimilated into celebrations of some of the other Roman traditions that took place in October, including a day to honor Pomona, the Roman goddess of fruit and trees. (which some feel is the link to the modern tradition of bobbing for apples on or around Halloween).
The thrust of the Samhain practices also changed over time to become more ritualized, and as belief in "spirit possession" waned, the practice of dressing up like hobgoblins, ghosts, and witches took on a more ceremonial role.
We then fast foward about eight centuries, when Irish immigrants fleeing their country's potato famine began arriving in America. As part of their Celtish legacy, they dragged along the residue of Samhain, which why the first evidence of Halloween in America conveniently tracks back to the 1840s.
Other European immigrants brought in the trick-or-treat element. That didn't originate with the Celts, but instead with a ninth-century European custom called souling. On November 2 -- All Souls Day -- early Christians would walk from village to village begging for "soul cakes," made out of square pieces of bread with currants. The more soul cakes the beggars would receive, the more prayers they would promise to say on behalf of the dead relatives of the donors. At the time, it was believed that the dead remained in limbo for a time after death, and that prayer, even by strangers, could expedite a soul's passage to heaven.
Hmmm...people trick or treat to help others get to heaven.
Why would a church want to boycott that?