There probably was and is an original source. But now, if you think that a COEXIST sticker is “cool”, you can get one through Amazon.
One has to be totally blind in one’s noetic eyes (”the eyes of one’s heart”; spiritual eyes) to think that a COEXIST sticker is “cool”. And by displaying a COEXIST sticker, one is spreading the disease of spiritual blindness! PHOOEY!!!!
I like the coexist sticker where the letters are made up of various armories and gun manufacturers logos