To this day Halloween is celebrated voluntarily. The U.S. Government does not recognize it. There is no national observance. It is not a paid holiday. It is kept alive through retail marketing, local school districts, city governments, and houses of worship.
People just do it.
Satanic ritual abuse, animal sacrifices, arsons, poisoned candy, cruel tricks, graffiti, etc. Decorating the house with images of the occult, witches, skeletons, etc. and dressing your children in costumes does not negatively affect your faith. You pass out candy to visitors, wish others a happy holiday, and enjoy the spookiness of the occasion. Even if you don't care to celebrate it, you enjoy seeing children having fun. Do nothing differently than on any other night.