Promise 14 Gen. 4:7

Gen. 4:7 - "If you do well, will not your countenance be lifted up? And if you do not do well, sin is crouching at the door; and it's desire is for you, but you must master it'." God is telling Cain that if he does well; makes the right choices, then he'll feel a lot better about it, but if he doesn't then the doors are opened up for sin to overcome him. There is a promise and a command in this verse. The promise is: If we do those things that are good, honest, holy and glorifying to God, we will feel good, we will feel full and lifted up. The command is: if we choose to do otherwise, then we open a foothold for the enemy. God didn't say we will be tempted, He said we will be succumbed to sin, but, He also said, "We must master it." Which to me means that it is I who opens the door to sin. The enemy doesn't open the door when we are doing good, it is when I do not make the right choices that sin enters in. I can't blame the enemy for what I've done, and I need to take hold of that sin and not let it overcome me. Just as I opened the door, I need to close it. God made it simple though, if you do good, you don't have to worry about the sin.