Cain doesn’t look for mercy from God. When David sinned with Bathsheba, and went so far as to have her husband Urriah killed, he was truly repentent. Psalm 51 tells David’s deep, heartfelt confession of sin and remorse. David agreed that he’d sinned against God. He pleaded with the Lord not to depart from him, and begged to be purged and cleansed. David promised to teach transgressors the way of the Lord.
Cain lacked the broken and contrite heart David mentions having in Psalm 51:17, though. Instead, he complains about the punishment. Whereas David humbly accepted the death of that child he had with Bathsheba, and the family problems later, as a just punishment, Cain tells the Lord that the punishment he would face was not going to work.
The most shocking part is that the part Cain complains most about - being a fugitive and vagabond - should have naturally occurred to him. This shows the lack of rationality not only in the murder, but the murderer’s thought patterns. One has to wonder just what Cain was thinking. Did he really have so much false pride that he thought others would naturally agree with what he’d done? Did he think nobody would care? Of course, he would be hunted down. He was the brother of the others who were born and/or would be born. But, he had also killed their brother.
This totally delusional thought process shows just how far mankind had fallen in just a few short years. They had gone from a perfect world, where they knew no sin, to these uncaring, despicable depths. Sin had truly spread throughout the entire world. The moral depravity would grow worse, sadly, till the mind of man was on evil continually. (Gen. 6:5)
