As with Adam, God exposes Cain’s corruption with a question, “Where is your brother?” The corruption of Adam is evident in Cain’s deceitful, hypocritical, insulting reply, “Am I my brother’s keeper?” The answer is yes, that IS the image of God which Jesus will live out and also teach: “Love your enemy.”
As with Adam and Eve, God explains the necessary, natural consequences of Cain murdering his brother. Cain complains that his guilt (and its consequences) is more than he can bear, so God puts a limit on the evil that will come back to Cain—just as God puts limits on all evil so that it still must work for good (Romans 8:28; 2 Corinthians 4:17-18; Jesus’ healing the demoniac in the Gadarenes in Matthew 8).