This has been an issue of great debate for a long as I can remember. I knew one brother in Christ, whose family would not celebrate Halloween because it worships the devil. There are some Christians, who enjoy dressing up as someone just for the fun of it. Some like it for the candy and I am just referring to the kids.
We even have churches that have some form of carnival for parents to bring their kids to get candy, play games, and maybe hear a gospel presentation. So there is some confusion with people in the church as well as those outside the church if Christians are to celebrate Halloween.
The following is from Grace To You which talks about the response Christians should have regarding Halloween:
First, Christians should not respond to Halloween like superstitious pagans. Pagans are superstitious; Christians are enlightened by the truth of God's Word. Evil spirits are no more active and sinister on Halloween than they are on any other day of the year; in fact, any day is a good day for Satan to prowl about seeking whom he may devour (1 Peter 5:8). But "greater is He who is in you than he who is in the world" (1 John 4:4). God has forever "disarmed principalities and powers" through the cross Christ and "made a public spectacle of them, triumphing over them through [Christ]" (Colossians 2:15).
Second, Christians should respond to Halloween with cautionary wisdom. Some people fear the activity of Satanists or pagan witches, but the actual incidents of satanic-associated crime are very low. The real threat on Halloween is from the social problems that attend sinful behavior—drunk driving, pranksters and vandals, and unsupervised children.
Like any other day of the year, Christians should exercise caution as wise stewards of their possessions and protectors of their families. Christian young people should stay away from secular Halloween parties since those are breeding grounds for trouble. Christian parents can protect their children by keeping them well-supervised and restricting treat consumption to those goodies received from trusted sources.
Third, Christians should respond to Halloween with gospel compassion. The unbelieving, Christ-rejecting world lives in perpetual fear of death. It isn't just the experience of death, but rather what the Bible calls "a certain terrifying expectation of judgment, and the fury of a fire which will consume [God's] adversaries" (Hebrews 10:27). Witches, ghosts, and evil spirits are not terrifying; God's wrath unleashed on the unforgiven sinner—now that is truly terrifying.
Christians should use Halloween and all that it brings to the imagination—death imagery, superstition, expressions of debauched revelry—as an opportunity to engage the unbelieving world with the gospel of Jesus Christ. God has given everyone a conscience that responds to His truth (Romans 2:14-16), and the conscience is the Christian's ally in the evangelistic enterprise. Christians should take time to inform the consciences of friends and family with biblical truth regarding God, the Bible, sin, Christ, future judgment, and the hope of eternal life in Jesus Christ for the repentant sinner.
There are several different ways Christians will engage in Halloween evangelism. Some will adopt a "No Participation" policy. As Christian parents, they don't want their kids participating in spiritually compromising activities—listening to ghost stories and coloring pictures of witches. They don't want their kids to dress up in costumes for trick-or-treating or even attending Halloween alternatives.
That response naturally raises eyebrows and provides a good opportunity to share the gospel to those who ask. It's also important that parents explain their stand to their children and prepare them to face the teasing or ridicule of their peers and the disapproval or scorn of their teachers.
Other Christians will opt for Halloween alternatives called "Harvest Festivals" or "Reformation Festivals"—the kids dress up as farmers, Bible characters, or Reformation heroes. It's ironic when you consider Halloween's beginning as an alternative, but it can be an effective means of reaching out to neighborhood families with the gospel. Some churches leave the church building behind and take acts of mercy into their community, "treating" needy families with food baskets, gift cards, and the gospel message.
Those are good alternatives; there are others that are not so good. Some churches are using "Hell House" evangelism to shock young people and scare them into becoming Christians. They walk people through rooms patterned after carnival-style haunted houses and put sin on display—women undergoing abortions, people sacrificed in a satanic ritual, consequences of premarital sex, dangers of rave parties, demon possession, and other tragedies.
Here's the problem with so-called Hell House evangelism: To shock an unshockable culture, you have to get pretty graphic. Graphic exhibits of sin and its consequences are unnecessary—unbelieving minds are already full of such images. What they need to see is a life truly transformed by the power of God, and what they need to hear is the truth of God in an accurate presentation of the gospel. Cheap gimmickry is unfitting for Christ's ambassadors.
There's another option open to Christians: limited, non-compromising participation in Halloween. There's nothing inherently evil about candy, costumes, or trick-or-treating in the neighborhood. In fact, all of that can provide a unique gospel opportunity with neighbors. Even handing out candy to neighborhood children—provided you're not stingy—can improve your reputation among the kids. As long as the costumes are innocent and the behavior does not dishonor Christ, trick-or-treating can be used to further gospel interests.
Ultimately, Christian participation in Halloween is a matter of conscience before God. Whatever level of Halloween participation you choose, you must honor God by keeping yourself separate from the world and by showing mercy to those who are perishing. Halloween provides the Christian with the opportunity to accomplish both of those things in the gospel of Jesus Christ. It's a message that is holy, set apart from the world; it's a message that is the very mercy of a forgiving God. What better time of the year is there to share such a message than Halloween?