Evil and darkness are real
The Bible is pretty clear that evil and darkness are real. They are the very things that stand in opposition to God. If God is light (1 Jn 1:5) and good (Mk 10:18), then evil and darkness are those things that stand in opposition to him (1 Jn 3:8ff). The Devil himself both orchestrates certain acts of evil and influences those that belong to him (Jn 13:2; Eph 2:1-3; Eph 6:11f; 2 Tim 2:24-26; 1 Pet 5:8f; 1 Jn 3:8-10).
Nowhere does the Bible talk about gruesomeness, ghosts of the departed or monsters as particular examples of evil. Rather, the evil with which the Bible is concerned is opposition to God. It is seen first in our response to Jesus; whether we will accept him as Lord or not. It is then seen in our actions that result from this decision to be found in Christ or against him (Mt 12:30-32). The Devil delights in lies, indeed he is a deceiver by nature (Jn 8:44), and his greatest pleasure is to keep you from trusting Christ and following after God. This is the evil and darkness we should be sure to flee.
Celebrating evil and darkness is perverse
The dressing up, sweets and stories of things that go bump in the night obscure the real issue. In and of themselves, there is nothing to worry about in silly monsters and costumes. If these are your central concern about Halloween then I have some great news for you: the zombies, ghouls and monsters in which Halloween revels aren't real. If you are scared by such things, there is nothing to fear in that which doesn't exist. Paul makes this same argument in relation to idols and false gods (1 Cor 8:4-6). We can eat food offered to other supposed deities without anxiety because they aren't real and don't actually exist. They are nothing thus we have nothing to fear.
But the heart of the matter is not the costumes, the monster and the stories. The real issue is what lies behind such things. Halloween is, fundamentally, a celebration of evil. As Canon J.John comments here, when costumes cover "a chainsaw killer, a psychopathic butcher or even a shooting victim (‘with authentic-looking bullet holes’).This is hardly harmless." It is a move beyond fictional stories to glorifying and reveling in real and grotesque evil. As J.John notes:
"In some older Halloween traditions people dressed up in clothes that made them look evil and then, at the end of the evening, the outfits were burnt. The message was clear if naive: in the end, good triumphs over evil. Yet there is no hint of that in the modern Halloween. Now, evil is unchallenged and just slips away into the darkness, to return at some other time."There is something perverse about the celebration of evil. It amounts to a celebration of the works of the Devil. The Christian really shouldn't have any part in celebrating that which the Devil stands for (2 Cor 6:14ff).
The Christian has no cause to fear
As we've already seen, if your fear of Halloween stems from the costumes and stories of ghouls and monsters then we really have no cause to fear. Such things aren't real. Yet - as we said at the beginning - evil, darkness and the Devil are real. They are things to be taken seriously. Does that mean Christians have cause to fear?
The short answer is 'no'. Jesus himself tells us:
My sheep hear my voice, and I know them, and they follow me. I give them eternal life, and they will never perish, and no one will snatch them out of my hand. My Father, who has given them to me, is greater than all, and no one is able to snatch them out of the Father's hand. (Jn 10:27-29)There is no way the Devil can take those who belong to Christ away from Him. Paul offers us this same assurance in Romans 8:38f. Again, Jesus tells us not to fear the Devil or any who belong to him (Mt 10:24-28; Lk 12:4f). Indeed, one of the signs that we have received God's Spirit is that we don't fear sin, death or the Devil any longer (2 Tim 1:7; Heb 2:14f; 1 Jn 4:17f; Rev 2:10).
John Knox famously said "I have never once feared the devil, but I tremble every time I enter the pulpit". Knox had grasped the true meaning of Proverbs 1:7, 29 & Mt 10:28. The believer has nothing to fear in the Devil. Jesus has already won the victory over his most powerful weapons: sin and death. Yet proper proclamation of God's inspired word is a serious task indeed.
So, the Christian has nothing to fear in Halloween. We will not get swept away with the Devil simply because it happens around us. Nor will we be dragged away if we try to use it as a means of proclaiming the gospel to those who decide to take part. Is it something I would encourage us to join in? Probably not. Is it an event that should cause to tremble? By no means.