Halloween is a disputable matter (Romans 14). Three defensible Christian positions exist. What you actually do matters more than the calendar date. 50/100 Mixed.
Abstain: Not participating because of pagan roots, celebration of death and the occult, and normalization of darkness. Ephesians 5:11: have nothing to do with deeds of darkness. Redeem: Engaging redemptively — Harvest Festival alternatives, trick-or-treating as neighbor connection — treating it like Paul treating meat sacrificed to idols (1 Corinthians 10:25-30). Participate Selectively: Children in animal costumes trick-or-treating is different from haunted houses and occult themes — participate in the innocent aspects, avoid the dark ones.
Romans 14:5-6: 'One person considers one day more sacred than another; another considers every day alike. Each of them should be fully convinced in their own mind.' Christians should not divide over Halloween or judge those who participate differently. Whatever your position: avoid occult content (fortune telling, seances), genuine glorification of death, and genuinely frightening content for young children. See our Is It a Sin? hub.
For a thorough evangelical overview: GotQuestions on Halloween.