God’s message of grace can be traced back to the beginnings of human history. Even when God approaches Cain, one of the original sinners, He encourages him! He tells Cain that He will be accepted if he does the right thing. Essentially, God pleads with Cain, asking him to choose God, choose to do this thing the right way. We always have a choice. It is in our power to do what is right. Watch out for sin and choose to not let it be your master.
You will be accepted if you do what is right. But if you refuse to do what is right, then watch out! Sin is crouching at the door, eager to control you. But you must subdue it and be its master.”
~ Genesis 4:7 [NLT]