Originated from The Simpsons. Generally used by the general public and webcomic authors so as not to spark religious debate. It does not "use the Lord's name in vain," and gets the message across.
Psyguy: Save meh, Jebus!
the earlyest referance found was in The Old Testament of the Bible where it mentions a people called the Jebusites
Jebus has also been referanced as the original place name of Jerusalem until it was conquered by the Israelites.