Evil came about when this woman named Pandora got a little too curious and opened up a box she found in her grandpappy's attic hidden behind the mannequins dressed as farmhands.
She opened the box and all manner of evil, including; but, not limited to sloth, pride, glutton, fibbing, thievery and playing tiddlywinks on the Sabbath.
Soon the world was awash in evil and God said it was time to create something called Free-will (not to be confused with the movie about a whale named Free Willy, which was about how Jonah captured Willy in retaliation for the whale having gobbled him up years earlier). With free-will, god could now let people do as they please and only intervene when he/she/unknown entity felt moved to do so. The rest would be sorted out when st.Peter Piper picked a peck of pickled peppers. Newcomers arriving at Pete's garden gate had to correctly name the hour in which they'd become pickled. Following that, there's a trial which is more for show than anything else as God or Godel or possibly Arthur Godfrey had already decided the sinner's fate.
Another theory based on a man written story says God tossed Lucky (Lucifer) out one afternoon for impure thoughts towards Hera. After that day, God felt depressed and stopped tending to the humans, letting them do as they pleased.