Background

Cain is the eldest son of Adam and his second wife, Eve, having been born shortly after Adam and Eve were cast out of Eden. From an early age, Cain had to watch as his younger brother, Abel, was favored by the angels from heaven. As time went on, Cain became more and more resentful of his father and jealous of his brother. As he grew older, Cain became a dedicated farmer where as Abel becomes a shepherd.

It all came to head when both him and Abel gave offerings to god. In the end, god chose Abel’s livestock offering over Cain’s produce offering. Cain’s jealousy boils over. They end up getting into a fight and while Able tries to calm him down, Cain doesn't listen. The fight escalates until he picks a rock and bashes Abel over the head with it. While it didn't initially kill Abel, Cain procceded to hit Abel over and over again with a rock which does end up killing him. For his murderous act, Cain was cursed by God and upon his death, was damned to hell, becoming the very first sinner.