Whether it is okay for Christian Believer's to observe and celebrate a festive holiday and myths that feature more of the dark side of the spiritual world than not has and will, like many other not so scriptural friendly and God promoting acts and compromises, always come down to the heart''s intent of each person. I believe God Refers to it as "The Motive Of The Heart".

Conviction

Maybe a better word is conviction? But sadly, it has been my experience I would say that no matter what the teachings or historically accurate origins of any Festival and/or Holiday are exposed and/or taught and shared, everyone will most likely and ultimately justify just about anything they want to partake in.

Only the Holy Spirit and the Word of God can convict us regarding the proper behavior and actions for us to observe and/or partake in.

As for me, I always want to be ready to share my God inspired feelings, spiritual obedience and scriptural beliefs towards God 1 Peter 3:15 whenever the opportunity presents itself.

But of course in doing that, we will more often than not, open ourselves up to strong pushback from anyone that does not agree with our views. Worse, they will undoubtedly proclaim that you should not judge others.

A misguided reply between judging vs discernment to be sure but best left for another day and/or teaching.

Correctly Sharing

So, I've come to take the stance that should someone ask ( or seek ) my thoughts on any controversial matter I will certainly be happy to share my own beliefs/thoughts with them but moreover make it a certainty to turn towards "what does the bible say" about.

Please note that I'm only talking about a "Born Again" Christian Believer here. Someone who has experienced and accepted Jesus Christ as their savior John 3:3 and have a heart towards what He has done for them. ( notice the word "see" in that verse )? There are too many who regard themselves as Christians based solely on their agreement with the religious positions and/or church affiliations. Before becoming "Born Again" Romans 10:9 I certainly regarded myself as a Christian simply because thats what I was told I was.

Luke Warm

Then there's the witness ( or lack thereof ) of many believers that are so casual in their faith walk ( and study* of scripture ) that they are hardly distinguishable from the world in the way they live even AFTER they come/came to Christ.

* sparse reading and seldom ( if at all ) meditating on God's word.

The latter being even more unlikely to feel conviction and/or change by repenting and turning away from as much as the world as possible. Add to that how we see so many preachers, teachers and local churches whipping up so many substitute events that are just a parody of what the world is doing.

Summary

So, rather than my posting a definitive yes or no, regarding if a believer should or should not mix what the Bible reveals to us concerning God's character and being, with a worldly holiday in their homes and among their little ones, I find the best advice to be ( along with most GOOD teachers ) is to simply let the scriptures ( God Himself ) John 1:1 express His views for each of us to respond to in kind.

To borrow ( and slightly modify ) a quote from a famous pro football coach : "God is looking for volunteers not hostages."

Seems that, like the ancient Israelites, we are always looking to just live by and debate the letter of God's laws as just a rule without bothering to learn the heart of it...

Maybe instead of arguing over what is allowed by God and what is not, we might just ask ourselves this question:

Would Jesus observe and honor Halloween? And, does His Spirit appear to align with the outward markers, signs and practices of this popular Holiday?