Cain and Abel were the children of Adam and Eve. As a tribute to God, Cain, a farmer, offered portions of his crops to God as sacrifice while his brother Abel, offered the fattest portion of his flocks. Enraged that God preferred Abel's sacrifice, Cain murders his brother. God then exiles Cain from his home to wander in the land east of Eden, but marks Cain to protect him from the wrath of other people..

This story serves as the most rudimentary explanation of Good vs. Evil. Here we have Cain represent evil while Abel represents good, Cain's deception and murder stand out to the reader as the ultimate testament of Evil and God's mercy on and judgement on Cain exemplify the ultimate "good" in the world.
For me it is easy to shoot holes in any piece of work, whether it be biblical or otherwise, what stands out to me is the importance of this piece of work and the translation to modern times. Something specific I seem to grab from this piece of work is the mercy God took on Cain despite his murder. The fact that God did not kill a murder juxtaposes our current method for dealing with murder through the death penalty. For me in affirms  my position against the death penalty. For me religion stands as a set of rules that cannot be blindly followed, it is meant to be questioned and translated into our current era and constantly expounded upon. It is our duty, regardless of whether or not we believe in religion, to have a good moral compass. For those who do abide by a religion, it serves as a set of guidelines that help us distinguish between right and wrong; while some aspects of it may arguably be extreme or 'contrived' the essential message remains the same: Don't participate in evil; always keep a good moral compass.