John Calvin on Genesis 4:14

14. Every one that findeth me . Since he is no longer covered by the protection of God, he concludes that he shall be exposed to injury and violence from all men. And he reasons justly; for the hand of God alone marvelously preserves us amid so many dangers. And they have spoken prudently who have said, not only that our life hangs on a thread, but also that we have been received into this fleeting life, out of the womb, from a hundred deaths. Cain, however, in this place, not only considers himself as deprived of God’s protection, but also supposes all creatures to be divinely armed to take vengeance of his impious murder. This is the reason why he so greatly fears for his life from any one who may meet him; for as man is a social animal, and all naturally desire mutual intercourse, this is certainly to be regarded as a portentous fact, that the meeting with any man was formidable to the murderer.