Do not be yoked together with unbelievers. For what do righteousness and wickedness have in common? Or what fellowship can light have with darkness? 2 Corinthians 6:14
We are called to light in the darkness and not to participate in it. On Halloween, Christians must extinguish the darkness, not spread it, neither extinguish the light. Do not be unequally yoked with unbelievers, this means that we are not associated with them in their evil. Jesus went out with all people, but He did not participate in their sin, not even for a night of fun, games, and candies.
“I have the right to do anything,” you say but not everything is beneficial. “I have the right to do anything”but not everything is constructive. 1 Corinthians 10:23
No one is stopping you from celebrating Halloween. However, it is necessary to consider whether it is beneficial for you as a Christian. What redemptive qualities do you find in it? Would Christ celebrate this tradition? How is Jesus glorified and Satan defeated when we celebrate? Examine your heart, search the Scriptures and ask the Holy Spirit: Do you like me celebrating Halloween?