Summary: In this chapter we learn of the anquish that sin causes, why Cain’s offering was rejected by God and how his attitude reveals what was in his heart - and the choices he made because of that attitude.
Chapter 3 shows the fall of human kind and the infection of sin and the infiltration of sin.
Chapter 4 shows the fall of the family and the impact of sin
We move from unrepentant Cain to defiant Lamech
Chapter 5 shows the attempts of man to counteract the fall while living in sin
Overall chapters 4 and 5 show our refusal to be held accountable
Vs 1 - 2a
We really don’t know if Adam and Eve had intimate relations before or after their ejection from the Garden of Eden - it may have come about years later - we really don’t know. What we do know is that they had two boys (now perhaps at the same time they were having daughters that aren’t listed).
Vs 2b - 7
God doesn’t tell us all we want to know - just what we need to know.
Both were worshiping God.
It was an offering, not a sacrifice. There is nothing in the text that tells us that the offering itself was faulty - nor that Abel’s was a "blood" sacrifice. It was a freewill offering.
The offering was by "faith":
Hebrews 11:4 (quickview)  By faith Abel offered God a better sacrifice than Cain did. By faith he was commended as a righteous man, when God spoke well of his offerings. And by faith he still speaks, even though he is dead.
Something was wrong in Cain’s heart, not his hands. It was Cain’s response to God saying "no" to his offering - it was an attitude. Cain wasn’t coming in faith - why would you come to God otherwise?
1. Social pressure
3. Get something from God
You can often tell where a person’s heart is when God says no.
"sin crouching at the door, it desires to have you." There is suggestion in the Hebrew wording here to suggest that demonic doorway forces actually waited for Cain to make a decision - does he give way to it, or does he master it. Satan’s forces are always there, tempting us according to our predisposition to sin - and always there to make the way to sin smooth - when in reality the doorway to sin is a doorway to domination to sin.
"Desire" same word used earlier for Eve’s relationship with Adam- to compete and control.
This was the first murder - and is archetypal of Satan who wants to kill God but can’t so he gets Cain to kill that which is made in God’s likeness. Lying is also archetypal of Satan, the "father of lies." Often lies come right after sin - it’s the only way to keep on sinning - by covering up what we did.
Vs 8 - 9
Cain lies outright - then evades the blame - the same thing Adam and Eve did in the garden - I wonder where they learned it? What are you patterning for your kids when it comes to taking responsibility for your sins?
How do you react when God calls you on sin?
Cain is actually very angry, rude and contemptuous to God. "Keeper" is the same word used for Adam’s job description in the Garden. Cain, and the flesh, rejects God’s call.
Cain was not an atheist - but he was an unbeliever. He had some kind of relationship with God, but his heart was not given to God, nor did he agree with God’s way - he wanted his way.