Why do it? There are all sorts of false claims perpetuated about Halloween by Christians—really bad history.
It’s like we get into this weird conspiracy mindset and actually invent history to promote our view.
I’ve heard so many different ideas of the history of Halloween that I don’t know what to believe! Some say it is Satan’s holiday and others show that it has been celebrated as a church holiday used to celebrate the early saints (“All Saints Day”) !
Nevertheless, there is no question that the current celebration of Halloween has a lot of junk associated with it. So, when our kids were all very little, we didn’t participate in it. Instead, we had a special movie night and ate pumpkin pie together.
Now that the kids are getting older, we let them participate as a family witness. For example, we've given out candy with scriptures on them and the kids dressed in fun outfits, not dark ones. Joshua dressed up as a Chik-fil-a cow (I called him a bull!) one year. He was adorable!
I discourage decorating according to dark/evil themes. But pumpkins and fall decorations are appropriate. In other words, don’t celebrate evil in any way. But as long as people are knocking on your door, give them something from the Lord and use it as an evangelism opportunity.