4:1 The word “knew” means “had sexual intercourse with” and is the perfect description of what sexual union means—oneness and total knowledge of the other person. Sexual intercourse is the most intimate of acts, sealing a social, physical, and spiritual relationship. That is why God has reserved it for marriage alone.
4:2 No longer was everything provided for Adam and Eve as it was in the Garden of Eden, where their daily tasks were refreshing and delightful. Now they had to struggle against the elements in order to provide food, clothing, and shelter for themselves and their family. Cain became a farmer, while Abel was a shepherd. In parts of the Middle East today, these ancient occupations are still practiced much as they were in Cain and Abel’s time.
4:3-5 The Bible does not say why God did not accept Cain’s gift. Perhaps Cain’s attitude was improper, or perhaps his gift was not up to God’s standards. Proverbs 21:27 says, “The sacrifice of the wicked is abomination: how much more, when he bringeth it with a wicked mind?” God evaluates both our motives and the quality of what we offer him. When we give to God and others, we should have a joyful heart because of what we are able to give. We should not worry about how much we are giving up, for all things are God’s in the first place. Instead, we should joyfully give to God our best in time, money, possessions, and talents.
4:6, 7 How do you react when someone suggests you have done something wrong? Do you move to correct the mistake or deny that you need to correct it? After Cain’s gift was rejected, God gave him the chance to right his wrong and try again. God even encouraged him to do this! But Cain refused, and the rest of his life is a startling example of what happens to those who refuse to admit their mistakes. The next time someone suggests you are wrong, take an honest look at yourself and choose God’s way instead of Cain’s.
4:7 For Cain to subdue the sin that was waiting to attack and destroy him, he would have to give up his jealous anger so that sin would not find a foothold in his life. Sin is still waiting to attack and destroy us today. Like Cain, we will be victims of sin if we do not master it. But we cannot master sin in our own strength. Instead, we must turn to God to receive faith for ourselves and turn to other believers to receive encouragement and strength. The Holy Spirit will help us master sin. This will be a lifelong battle that will not be over until we are face-to-face with Christ.
4:8-10 This is the first murder—taking a life by shedding human blood. Blood represents life (Leviticus 17:10-14). If blood is removed from a living creature, it will die. Because God created life, only God should take life away.
4:8-10 Adam and Eve’s disobedience brought sin into the human race. They may have thought their sin—eating a piece of fruit—wasn’t very bad, but notice how quickly their sinful nature developed in their children. Simple disobedience quickly degenerated into outright murder. Adam and Eve acted only against God, but Cain acted against both God and other people. A small sin has a way of growing out of control. Let God help you with your “little” sins before they turn into tragedies.
4:11-15 Cain was severely punished for this murder. God judges all sins and punishes appropriately, not out of vengeance, but because he desires to correct us and restore our fellowship with him. When you’re corrected, don’t resent it. Instead, renew your fellowship with God.
4:14 We have heard about only four people so far—Adam, Eve, Cain, and Abel. Two questions arise: Why was Cain worried about being killed by others, and where did he get his wife (see 4:17)?
Adam and Eve had numerous children; they had been told to “replenish the earth” (1:28). Cain’s guilt and fear over killing his brother were heavy, and he probably feared repercussions from his family. If he was capable of killing, so were they. The wife Cain chose may have been one of his sisters or a niece. The human race was still genetically pure, and there was no fear of side effects from marrying relatives.
4:15 The “sevenfold” vengeance means that the person’s punishment would be complete, thorough, and much worse than that received by Cain for his sin.
4:19-26 Unfortunately, when left to themselves, people tend to get worse instead of better. This short summary of Lamech’s family shows us the variety of talent and ability God gives humans. It also presents the continuous development of sin as time passes. Another killing occurred, presumably in self-defense. Violence was on the rise. Two distinct groups were emerging: (1) those who showed indifference to sin and evil, and (2) those who called upon the name of the Lord (the descendants of Seth, 4:26). Seth would take Abel’s place as leader of a line of God’s faithful people.