He destroyed those who would live in an imperfect world, battling sin forever. If the woman ate from the tree out of desire for a better life, Kayin killed Hevel out of a lack of desire for a better life. His motive was self-destruction. The will to defy G-d's warning in an open rebellion. B'reishis leaves us with two models for sin.
Some sins emerge from delusion, either internal or external.
We sin because we believe we will be better off as a result of the sin. This sin can be avoided by merely knowing the difference between good and evil and choosing good. Other sins come from our rejection of life itself, its value, and our place within it. We reject G- d not through subterfuge, but directly. We will not except our position in his world.