Cain received mercy after mercy. God was patient with Cain, but Cain refused to repent. Thus God cursed Cain. This curse could be seen as yet another act of mercy (since God would have been perfectly just if He had simply ended Cain's life). But even after this act of mercy, even after this curse, Cain still refused to repent— he did not even show a sign of remorse:
Cain said, to the LORD, "My punishment is too great to bear! (Genesis 4:13)Cain failed to see that he fully deserved the curse. Instead, Cain saw the punishment as unjust and continued his complaint:
Behold, You have driven me this day from the face of the ground; and from Your face I will be hidden, and I will be a vagrant and a wanderer on the earth, and whoever finds me will kill me. (Genesis 4:14)Cain's concern was that he might be murdered. Yet, he still showed no concern over the fact that he had just murdered his own brother. Cain's thoughts were focused entirely on himself.
Does this not show the wickedness of the human race? Of the first two sons of Adam mentioned in Scripture, one was an unrepentant murderer! It seems the children of Adam and Eve would have had no problem living righteous lives. The world was not yet filled with an abundance of wicked men seeking to lead them astray. They likely heard the firsthand account of the fall from Adam and Eve... multiple times. But the nature of man had been corrupted. Even if Cain had heard the account of the fall directly from his parents, it failed to penetrate his stony heart.
Surprisingly, even after Cain's complaint, God replied to Cain in mercy:
So the LORD said to him, "Therefore whoever kills Cain, vengeance will be taken on him sevenfold." And the LORD appointed a sign for Cain, so that no one finding him would slay him. (Genesis 4:15)Not only did God listen to Cain's complaint, but God responded to Cain's complaint. Cain feared that he would be killed by another (for he had killed his own brother), so God appointed a sign for Cain. Whatever this mark was, it must have been visible enough so that any man who saw Cain would decide against slaying him.
Sadly, even after God's remarkable demonstration of mercy, Cain's pattern of failing to repent continued. Doubtless, it would have been impossible for Cain to remain in the same area among people who knew the details of his crime, so Cain left the area in which he lived. He settled in the land of Nod (an unknown location):
Then Cain went out from the presence of the LORD, and settled in the land of Nod, east of Eden. (Genesis 4:16)
Who was Cain's wife? - Genesis 4:17
Cain and Abel: Cursed - Genesis 4:10-12
The Fall: Merciful Curses - The Christian Worldview
Why Is Sin Unavoidable? (Part 1) - The Christian Worldview
The Fall: No Repentance - The Christian Worldview