Most God-Believing families don't observe pagan holidays.
My neighborhood : Trick or Treat families = 99.9% High rate of Pagan Holiday observing families. Most of these families are good, Christian families. Even the churches here in Cumming, Ga (including the good, old Southern Baptist ones) had Halloween parties for the children. [BTW, Santa Claus has been known to show up at the Christmas parties at the churches.]
Does Santa visit you home? Has the Easter Bunny has ever stopped by your house? The Tooth Fairy? Has Jack Frost paid a visit to your lawn on a crisp fall morning? Did you ever look at a rainbow with your kids and mention the pot of gold at the end? What about St. Patrick's day? The leprechaun wasn't a disciple. Did you or your kids ever dance around the Maypole at school? (am I dating myself?). You have never read your kids Fairy Tales (Hansel & Gretel, Sleeping Beauty, Cinderella et al?--)
Face it, all of our religious holidays & most of our social customs have a pagan remnant. Somewhere along the way, the message became "And God said, let there be no fun in life." And having fun, innocent fun became a sin.
God judges us, not other Christians. Certainly, not atheists. My question was a valid one. Whether or not the children in a religious home go trick or treating should be a non-issue to an atheist. He doesn't have a dog in that fight so to speak.