Our word for today helps us understand why Cain didn’t just make things right with God. In Genesis 4 we clearly see that he had both the ability and choice not to sin. God says in verse 7 “If you do well, will you not be accepted?” this was after God had accepted Abel’s offering but rejected Cain's. So, we can’t accuse God of not giving Cain an opportunity to do the right thing. So then why in the world would Cain choose to allow his anger to consume him to the point where he murdered his brother? It is because of sin’s desire to control us as God loving warns Cain of this very danger in the rest of this verse Genesis 4:7 “If you do what is right, will you not be accepted? But if you do not do what is right, sin is crouching at your door; it desires to have you, but you must rule over it.”
The word that describes sin’s posture against Cain and all of us is רבץ lie down, stretch oneself out, crouch, lie in wait, in ambush, lurk. It is used 30 times in the Old Testament. A good picture of our word is used in Genesis 49 to describe the actions of a lion. Genesis 49:9 “Like a lion he crouches and lies down”. Satan is compared to a lion in 1 Peter 5:8 “Be alert and of sober mind. Your enemy the devil prowls around like a roaring lion looking for someone to devour.” Now that is a frightening thought but there is good news in the next two verses. 1 Peter 5:9-10 “Resist him, standing firm in the faith … And the God of all grace, who called you to his eternal glory in Christ, after you have suffered a little while, will himself restore you and make you strong, firm and steadfast.” So just like Cain we have a choice we don’t have to let anger lead us into sin and away from God. God is there for us to strengthen us to chose him instead of sin.
What door would God be referring to that sin is lurking next to? I think he is talking about our heart. Not letting sin into our heart through anger. Anger like our other emotions is a gift from God to help us process the painful experiences we deal with in this broken fallen messed up world. God desires to lead us to passion with our anger. So that our energy flows to good things that bring life both here and into the next. But sin desires to use our anger to lead us away from God into slavery and destruction. This is why God warns us through Paul in Romans 6:12-13, 18 “Therefore do not let sin reign in your mortal body so that you obey its evil desires. Do not offer any part of yourself to sin as an instrument of wickedness, but rather offer yourselves to God as those who have been brought from death to life; and offer every part of yourself to him as an instrument of righteousness … You have been set free from sin and have become slaves to righteousness.” This is also why God instructions us in Proverbs 4:23 “Above all else, guard your heart, for everything you do flows from it.” Our choice, like Cain’s, is to allow sin to master us that leads to death or we master our anger by becoming slaves of righteousness that leads to life.
