No one could identify the mark put on Cain, but God himself ,and that mark was the mark of vengeance or revenge if any one found him and killed him. To find somebody you have to be looking for them. God made him the first fugitive that would be running from justice,because he was a murderer , the first murderer. which turned him into a vagabond which means moving from place to place with an unsettled mind. If someone did find him and killed him, his death would be avenged seven-fold. That God would have taken care of himself. through the process of time ,I believe that Adam sent out some of his sons to hunt down Cain and kill him to avenge Abel's death. And God knew this would happen ,that's why he made him a fugitive.he was not a fugitive from God, because God knew his whereabouts at all times.He set up the city of Enoch, named after his first son, and hit the road . I do believe that someone did kill Cain ,because he told his Son about the mark and the vengeance.. The story was past on,because the fourth generation grandson Lamech was injured in a fight that wounded him,and that wound was a fatal wound.. On his dying bed ,he told his two wives that he had killed a man that wounded him,and that if Cain's death shall be avenged seven-fold, then his death would be avenged seventy and seven -fold. During that time, men was not worshiping and calling on God. Adam's descendants, and Cains descendants were at war with each other, because they were a different race of people . .They did not began to call upon the name of the lord until Seth's son Enos was born. Those that called upon his name became the son's of God, and they were powerful men taking the women of Cain's descendants when they wanted to.That is why God said his spirit shall not always strive with man, for that he also is flesh.that meant that God gave up on trying to change man and make him do better, but he realized that what kept that from happening is that his flesh was sinful ,causing him to do evil. Okay plan A did not work, so he set up plan B. He knew what he had to do to make this work.
