I celebrate Halloween...kinda...I was born on Halloween (It is strange to have been born on the day of the dead)
But, anyway, the concept of Halloween takes our sight away from celebrating the Lord. It does not have Christian origin, promotes mysticism and idolatry, etc. Eating candy, discussing death in the context of truth, all seem that they would be okay [as well as giving thanks for life and love]. But celebrating the day and what it represents does not seem to be. I also think that for many people it would be good to take this day aside simply in order to avoid the temptations associated with it. Have a fall festival, which a lot of churches do. This creates a disconnect from the idea of Halloween. let October 31st be October 31st, as any other day.