When the sin which Cain refused to recognize had worked itself out so that even he must recognize it as the terrible thing that it was from the beginning, then not only he, but all others recognized it as the great sin that it was. Therefore, Cain not only recognized that "My iniquity is greater than that it may be forgiven," (Genesis 4:13,margin) but also that "I shall be a fugitive and a vagabond in the earth; and it shall come to pass that every one that finds me shall slay me." (Genesis 4:14)
But in all this Cain had mistaken the Lord, as in all the other he had mistaken himself. There is with the Lord forgiveness of iniquity, and transgression, and sin. The Lord had given the Firstling of his flock, the Lamb of God, a satisfaction and propitiation for the sin of the world and for the sins of men. There was for Cain forgiveness full and free at the first, when he refused to recognize that there was in him any sin at all. There was for him forgiveness just as full and free after he had manifested his refusal to recognize that there was in him any sin at all, and when the Lord had in mercy revealed to him that "sin lies at the door." (Genesis 4:7)
In the Lord's sight the sin was no greater when it had worked itself out than when it lay at the door; no greater when it had made the spring and accomplished its awful stroke than when it lay at the door crouching ready to spring to its awful stroke. There was with the Lord then forgiveness full and free, and there was with Him now forgiveness just as full and just as free; for He changes not. (Malachi 3:6)
Therefore Cain's iniquity was not greater than that it might be forgiven; in reality no more so now than at the first. And this the Lord now makes manifest to him in such a marvelous manifestation of mercy that even not only Cain, but also all others could know it. To Cain's complaint the Lord answered, "Therefore whosoever slays Cain, vengeance shall be taken on him seven-fold. And the Lord set a mark upon Cain, lest any finding him should slay him." (Genesis 4:15)
And what a token of the blind perversity of the natural mind is given in the fact that in this marvelous extension of mercy to Cain there is seen by thousands even of professed Christians only an advertisement and condemnation of Cain and his guilt, and all emblazoned before the universe! These refer to "the mark of Cain" as if it were distinguishing blood-red mark of his guilt and condemnation branded upon him by God to enlist all men also in the condemnation; and according to this blind and perverse nation, they promptly enlist in the hue and cry of the condemnation of Cain and other sinners, and condemn themselves in their condemnation of him and others. In this blind perversity they overlook the divine and glorious truth that with God there is forgiveness, not condemnation, of sinners; that God gave not His son to condemn the world nor any man, but that the world and all men through him might be saved. (John 3:17)
Cain was guilty, that is true, and by his transgression and his guilt he was condemned accordingly; this he showed by his fearful complaint. But God did not add to the condemnation; added condemnation never helps anybody. No; the merciful God extended forgiveness; and merciful consideration so that the guilty one might be encouraged to believe in and receive the merciful forgiveness.
And the "mark" which "the Lord set" upon Cain was the full assurance to him and to all men that there was extended to him this merciful consideration and probation; for the word distinctly says that the Lord set this "mark upon Cain, lest any finding him should slay him." (Genesis 4:15)
It was thus the divine surety that no one should slay him. It was therefore a divine pledge of the divine protection; and in this it was the full assurance of the extension of merciful forgiveness, and of merciful consideration and probation in order that he might avail himself of the forgiveness and salvation of the Lord, "in full assurance of faith." (Hebrews 10:22)
And thus was the gospel in its blessed fullness preached to all the world in the case and for the salvation of the first open sinner in the world after The Fall.
And, sad to say, as for any faith and salvation of Cain, it was all in vain. Still through it all Cain remained unrepentant. Instead of allowing this marvelous mercy and goodness of God to lead him to repentance, (Romans 2:4) he made it rather the sanction of his continuance in hardness of heart and transgression.
This is not only declared by Inspiration in the words of Jude 1:11, "Woe unto them! For they have gone in the way of Cain, and ran greedily after the error of Balaam for reward, and perished in the gainsaying of Korah." but it shows itself in the life of Lamech the fifth in descent from Cain. "Lamech said unto his wives, Adah and Zillah, I have slain a man for wounding me, and a young man for hurting me: If Cain shall be avenged sevenfold, truly Lamech seventy and sevenfold." (Genesis 4:23-24,RV)
His argument is: "Cain slew an innocent man, one who had done him no hurt at all; and any slaying him would be avenged sevenfold. But this man wounded me, this man hurt me. If, then, Cain was protected and avenged sevenfold, who slew an innocent man, a man who had done him no hurt, truly I shall be protected and avenged seventy and sevenfold, when the man whom I slew had wounded me, and had hurt me."
Thus God's great mercy to the sinner was used only for the sanction of the sin; "turning the grace of our God into lasciviousness, and denying the only Lord God, and our Lord Jesus Christ." (Jude 1:4)
And this was only going "in the way of Cain"--still unrepentant and hardened. In the life of Lamech, the fifth from Cain, there appears another strain of evil: "Lamech took unto himself two wives." (Genesis 4:19)
Polygamy was thus begun. And thus, and so soon in unrepentant Cain and his family there was developed and confirmed the two crowning evils of the world: polygamy, that would annihilate the family and society, and would turn mankind into only a herd; and murder, that would annihilate mankind and the race itself.
Is it any wonder that in five more generations of such as these, the earth became so filled with violence and licentiousness that only the waters of the Deluge could effectually cleanse it, and that thus these two crowning evils did come within "eight souls" of annihilating mankind and the race?--Medical Missionary, August 19, 1908--Genesis 4:11.