My wife's late grandmother was ultra-religious (Methodist, teetotaler, WCTU - the whole nine yards) and also highly superstitious about certain things. She wouldn't adopt a black cat, refused to seat 13 people at a table, wouldn't walk under a ladder, etc. My mother-in--law (also very religious) once said, "I don't understand how a religious person could be so superstitious."
Hmmmm....