The pervasiveness of sin has increased dramatically between Genesis 3 and 4. One generation in and Cain cannot be talked out of sin. His heart is hardened toward God and his brother. God judges Cain's sin and yet is merciful to him, sparing his life. God's mercy continues through this chapter and is personified to us in the person of Jesus. Jesus is the son of Seth, the 2nd Adam who has come to bear our sin and defeat our common enemy.