It's traditionally a day to celebrate the dead.
Halloween (All Hallows Eve) actually originated as a Christian observance on the eve of All Saints Day, a day on which the orthodox churches traditionally remember those who have passed.
We Protestants have "thrown out the baby with the bath water," so to speak. When we broke away from the high church we rejected not only some of the doctrines but also the many rites and rituals and regalia of high church practice. We still observe the most basic "holy days," (Christmas and Easter for example), but because we have rejected the liturgical calendar we have lost the meaning behind many of the customs and traditions associated with these holidays. This has left us wide open to claims that our customs and traditions have pagan roots, when in fact they are very much rooted and grounded in how Christians through the ages have celebrated the times and seasons of our faith.
Just for an example ... eggs and Easter. No, the association of eggs with Easter has nothing to do with pagan spring fertility rites. Almost since the beginning of the church, Christians have practiced the very Biblically sound principle of fasting. We have written records dating back to within a generation of the Apostles that discuss Christians fasting from foods that are derived from animals (meat, dairy, eggs, etc.), especially in the season leading up to Easter. And one of the foods most commonly fasted from, and was in fact mentioned in the earliest writings, was eggs.
Now through the ages, families who fasted from eggs during the 40 days before Easter (called Lent) would find themselves with a surfeit of eggs, so the sensible thing to do would be to let the hens set the eggs so they didn't spoil and go to waste. And naturally, that means there would be a sudden boom of baby chicks being born in the days leading up to Easter. But then, as was the custom of Biblical times, the fast would end with a feast on the day of the Resurrection, Easter, and all the foods that one had fasted from would once more grace the dinner table, including eggs, which eventually Christians began to die different colors and hide for children to find to make the day more festive.
And that's how simply and innocently eggs and chicks came to be so much a part of our Easter celebration.
There was nothing pagan about all this. Instead our customs and traditions have come down to us through the ages by Christians living out their faith in simple ways and observing the times and seasons of Jesus' life.
Halloween, or All Hallow's Eve, is actually an old Christian observance.
Besides, if you take the materialization and secularization of Christmas as an example, it's not Christians who have adopted pagan holidays, it's pagans who have adopted Christian holidays ...
In Christ,
Pilgrimer