but the dead know not any thing....
Ecclesiastes 9:5
"In Mexico, Latin America and Spain, All Souls’ Day, which takes place on November 2, is commemorated with a three-day celebration that begins on the evening of October 31. 
The celebration is designed to honor the dead who, it is believed, return to their earthly homes on Halloween.
Many families construct an altar to the dead in their homes to honor deceased relatives and decorate it with candy, flowers, photographs, samples of the deceased’s favorite foods and drinks, and fresh water. Candles and incense are burned to help the deceased find the way home. Relatives also tidy the gravesites of their departed family members."
History