"Cain was the first human born on this planet.
He was also the first human to only know a fallen world.
Eve seemed very hopeful when she named him, saying, “I have gotten a man with the help of the Lord” (Genesis 4:1). She may have been looking forward to the fulfillment of God’s promise that one of her offspring would defeat the serpent (Genesis 3:14–15). 
Because he was the first child, and because he conversed directly with God, Cain had privileges that few other people in history have had.
While Abel gained a lasting reputation in Scripture as a righteous man and the first martyr of history, Cain is the archetypal murderer.
Yet there were bright spots even in Cain’s lineage. Music, metallurgy, and nomadic herding were innovations of Cain’s line, showing that a man’s descendants aren’t doomed to fruitlessness because of the sins of their forefather.
This can serve as a good lesson for us today.
Our ancestors, all the way back to Adam, were sinful people. ...We ourselves are sinful people ....We all deserve death. But Jesus died in our stead. Since we have been freed from the curse of death, we are now free to live as redeemed, transformed people in Christ." CMI
