When God judged Cain for the murder of Abel he became fearful for his life. The Bible speaks of God putting a mark on Cain to protect him from others.
And the Lord said to him, Therefore, whoever kills Cain, vengeance shall be taken on him sevenfold. And the Lord set a mark on Cain, lest anyone finding him should kill him (Genesis 4:15).
God’s mark of protection on Cain was to help provide for his safety. However, it did not prevent Cain from being attacked or murdered. The mark merely warned that anyone who killed Cain would himself suffer a worse death.
The fact that God had to put a mark on Cain suggests that the population was large enough that Cain needed to be singled out for protection. The text does not tell us what the mark was or that it was passed down to succeeding generations. As to what was the mark of Cain there have been a number of suggestions.
Not Necessarily On His Person
Certain Bible commentators have argued that the mark was merely a sign of confirmation that Cain would be protected from others. We are not told what sign God gave him, but whatever it was it calmed his fears for his life.
The phrase set a mark upon Cain (King James Version) does not necessarily mean that there was some mark upon his person. The phrase more likely means a sign for him. This could mean that God gave some sign to appear for Cain’s reassurance. Thus the idea of mark may mean some type of token or pledge. There are two other instances in the Old Testament where God gave similar signs to confirm His Word (Judges 6:36-40) and Elisha (2 Kings 2:9-12).
Appointed A Sign
The Revised Version translates the phrase appointed a sign for Cain. This indicates that whenever someone approached Cain some sign was given to deter that person from attacking. Though we are not told what this sign was, it protected Cain from those who wished to harm him.
Others have argued that the mark was something physical. This would either be on his person or something that was with him. Possible solutions include: a dog to provide direction for Cain, a physical mark on his forehead, horns, or a brightly colored coat. One of the horrible suggestions that has been made is that Cain was marked with black skin. There is absolutely no basis whatsoever for accepting this terrible interpretation.
None of these proposed solutions to the mark of Cain can be proven or disproven – we are simply not told what it was.
Mark On The Forehead
The prophet Ezekiel was told to put a mark on the foreheads of certain people.
And the Lord said to him, Go through the midst of the city, through the midst of Jerusalem, a put a mark on the foreheads of men who sigh and cry over all the abominations that are down within it (Ezekiel 9:4).
Scripture also tells us that in the future, God will mark His people for protection. For example, in the Book of Revelation we have an episode where people have a mark placed upon them. A special group of people, the 144,000, receives a mark from God that guarantees their protection. The Lord commanded:
Do not harm the earth, the sea, or the trees till we have sealed the servants of our God on their foreheads (Revelation 7:3).
Those not having the mark of God were not protected from the coming judgments.
Mark Of The Beast
In the Book of Revelation we also find the mark of the beast. Satan always counterfeits the things of God. As God marked the 144,000 as a special people to be protected, Satan will mark all those who worship him with his name and number on their right hand and forehead. As is true with the mark placed on the 144,000 by God, the mark here speaks of ownership.
And he causes all, both small and great, rich and poor, free and slave, to receive a mark on their right hand or on their foreheads (Revelation 13:16).
Both of these marks were for the purpose of keeping the people safe who received the mark. Therefore we can conclude that the mark of Cain fits other portions of Scripture where a mark is given as a sign of protection.
From God To Nod!
After his judgment, Cain went out from the presence of the Lord and built a city in the land of Nod. The exact location of Nod seems to be unknown to the readers of Genesis. It is described as being east of Eden. This is another geographical reference away from the Garden. As humankind goes further east, they go further from God’s presence.
Successful Materially, Not Spiritually
Thus this part of humanity, cut off from God’s presence, organized and built the first city. From the simple pastoral and agricultural life humankind now created urban society with all its complications. Cain’s city developed music and metallurgy. The mention of metal working at that very early period causes a problem because it occurs long before the historical bronze and iron ages. It is possible that the knowledge of metallurgy was wiped out in the Flood of Noah. The techniques discovered and employed in this time were then rediscovered at a later period.
Though this community was successful in material matters, their spiritual life continued to be far away from God’s presence.
The mark of Cain was to help keep him from being physically harmed while he was a stranger and a vagabond. It did not guarantee his safety, it only promised a worse fate for those who harmed him. We cannot be certain whether the mark was an actual physical sign or something else. Marking humanity is something we find in the Book of Revelation. God marks his people with a sign on their forehead. The Antichrist also marks his people with a sign on their forehead and right hand. In both instances, the marks indicated ownership and protection.