Why did Cain kill his brother? The Lord warned, “If you do what is right, will you not be accepted? But if not, sin crouches at the door.” Instead of taking up the battle against sin, Cain took up the battle against his brother Abel. On the other hand, Abel did not sin. Though it cost him his life, this unsung hero recognized that the battle wasn't with his brother, but with sin.
This concept returns in the book of Ephesians. “For we wrestle not against flesh and blood, but against […] spiritual wickedness in high places” (6:12). In other words, struggle with sin isn't struggle with other people, or even yourself. Instead, the battle with sin is a fight against spiritual forces of evil. This battle is won by Jesus Christ when you give yourself totally to him.
This raises two questions. First, how do you feel about your sin–if there be such? Do you make arguments in favor of sin, like, “God wants us to enjoy ourselves,” or, “Romans 7 says that we all sin.” Or did you declare war on sin?
Second, are you content with Jesus? If you are discontented with Jesus, this not only indicates sin, but is itself sin.
Are you free from sin today? If you will confess your sins out loud, declare war on all sin, and give yourself totally to Jesus, then God will give you the victory not just now, but forever! Then, like our unsung hero Abel, you will be willing to die rather than sin!