I think this principle is still alive and well today, one of the mainstays of Christianity philosopy - do not take revenge. God was telling us not to take the law unto our own hands because the matter of life and death is His.
We were told never to take the creation story in Genesis as scientific or historical book but rather to undertsand the message in the moral and the principle of the story. I think it’s because it is impossible to compress eon of years in a few pages of story.
That is an excellent point:
[Luke *17: 3-5] Take heed to yourselves. If thy brother sin against thee, reprove him: and if he do penance, forgive him. And if he sin against thee seven times in a day, and seven times in a day be converted unto thee, saying, I repent; forgive him. And the apostles said to the Lord: Increase our faith.
[Matthew 18: 21-22] Then came Peter unto him and said: Lord, how often shall my brother offend against me, and I forgive him? till seven times? Jesus saith to him: I say not to thee, till seven times; but till seventy times seven times.
For some reason some seem to not understand or completely misinterpret something that is crystal clear. To be honest the first thing that came to mind when I saw (anyone harms Cain, vengeance shall come to them 7 fold) were the two versus above (I choose not to post it though). If there is something that you don’t understand fully though it is best to stray away from interpreting it incorrectly and bringing yourself into error.
I would like make a reference about the Holy Trinity, it is something that we are truly unable to comprehend, and therefore should be faithfully accepted and not contemplated.
Your answer though hit the nail directly on the head.