Matt Mikalatos makes the case:
We tell monster stories because we’re afraid of what we are and what we could become. Werewolf stories are inevitably about what happens when a man loses the battle to control his "natural" urges. Vampire stories (at least traditional ones) are about selfish beings who steal blood to prolong their lives, the precise opposite of Christ, who gave his blood willingly to provide the chance of eternal life for others. Zombies are all about a perverted resurrection… an eternal life that isn’t worth living, because it’s a type of continual death.