Pagan Influence On Christianity

Pagans believe that the wandering spirits of the dead would return to their original homes in order to placate these spirits it was believed that you must feed them and provide them with shelter for the night otherwise you are in danger of harm hence the modern practice of Trick or Treat, bobbing for apples the hollowing out and lighting of pumpkins, cats, ghosts, goblins, death and a preoccupation with satanic paraphernalia on October 31st as filtered down from the ancient Scottish, Irish and Celtic custom surrounding samhain.
How did it ever become associated with Christianity? In the early 6th and 7th centuries the Catholic Church made it a practice to replace all pagan holidays with Christian celebrations in order to accommodate those