I have two younger brothers whom I love deeply. They were my best men at my wedding. So this story always managed to freak me out a little. I'm four years older than my younger brother and sometimes, like every once in a while, I might have employed mental warfare on him in order to get him to get me a cookie...but nothing that bad. Which is why this story always freaked me out a little bit.
Cain and Abel. The first set of brothers. Cain the farmer and Abel the shepherd (Gen 4.2). And then they both make offerings to God, and something not great happens
"In the course of time Cain brought to the Lord an offering of the fruit of the ground, and Abel also brought of the firstborn of his flock and of their fat portions. And the Lord had regard for Abel and his offering, but for Cain and his offering he had no regard. So Cain was very angry, and his face fell" Genesis 4.3-5 ESV
And Cain gets mad, but not normal mad, but mad like even The Incredible Hulk would say,"Bro..." He ends up killing his brother over his own jealousy. Humanity doesn't even make it two generations before there is murder. Dark. Just dark. So where is Jesus in all of this? Well, sometimes there is a shadow of what Jesus will do. Sometimes, like here, it is a shadow of what Jesus WILL REVERSE. I see him in this verse, which is God's follow-up talk with Cain after he murdered his brother.
"Then the Lord said to Cain, “Where is Abel your brother?” He said, “I do not know; am I my brother’s keeper?” And the Lord said, “What have you done? The voice of your brother’s blood is crying to me from the ground. And now you are cursed from the ground, which has opened its mouth to receive your brother’s blood from your hand." Genesis 4.9-11 ESV
So where is Jesus? Abel's blood cries to God to CONVICT sinners. Jesus' blood will later cry to God to REDEEM sinners.