What was the Mark of Cain? And was this mark a blessing or curse? The Book of Genesis does not go into the greatest detail on this but merely mentions that God placed it on Cain to protect him. It was a shield of sorts.
One can read the text of Genesis, chapter four, and see how the various events played out. Cain envied his brother Abel and killed him because God favored Abel and his sacrifice, whereas what Cain sacrificed (grains and plants) were rejected. We see in Genesis 4:10 to 4:14 that Cain is cursed and penalized severely but we can see from verse 15 that the mark placed on him is for his protection and no curse. It is not a further penalty or burden!!!
What was the nature of this mark? Was it a racial difference as some try to say? Was Cain turned into an ugly orgre or a Neanderthal like creature? (some actually say these things.). Most of these speculation are silly! The mark was a good thing and for the protection of Cain, despite his committing murder. One might even wonder if Cain was ultimately redeemed. Certainly the Lord cared for and provided for Cain. We don’t hear much more about Cain after some brief genealogies…..
Does the Hebrew text and the early Greek (Septuagint) give us any clues about the mark or sign? The Hebrew for mark in Genesis 4 is oth or ot and is “Strongs” number 226. This signifies a “mark” or “sign”. Note that the final letter for ot is the Hebrew letter Tav, which roughly corresponds to our “T”, and up to about 600 BC. this was a cross shaped letter, looking little like the latter squared Hebrew letter. Could the mark that the Lord placed on Cain be a cross? Some have suggested that this letter can alone indicate “covenant”. I think this is very likely and that Cain was actually repentant for his sins. The Septuagint text does not seem to help us determine anything extra. The word mark is rendered semion (semeion) or sign. It had to be visible enough to warn others so it was either an actual mark or something clear in Cain’s activities. Cain has been demonized down through time but he was probably no more sinful than King David or Saul of Tarsus.