Have you ever messed up?
I have. Big time. And I'm not alone.
When we mess up, when we miss the mark, when we "sin," we're tempted to think that God must be done with us. He must not want anything else to do with us. And certainly, we couldn't possibly believe we would inherit His promises or that He would continue to be good to us. Why would He? We don't deserve it.
But the beauty about grace is that we never deserved it. That's why it's called grace. And when we're tempted to think that perhaps God is done with us, perhaps He wants nothing else to do with us, perhaps we have lost His goodness forever, we need to look again at the way that God dealt with Cain.
Cain is the first murderer in the Bible. (Not the last, of course, but the first.) He killed his brother, Abel, out of nothing more than simple jealousy, and as a result of his crime, God casts him out into a land unknown and unworked. And Cain laments. How can he bear this? he asks. He will be far from the presence of God with nothing and no one to protect him from someone who might do the very same thing to him.
Then God, in His grace, shows His goodness even to Cain. He tells the young man, no. No, there will be no vengeance on you. Because even though you have messed up, you still hold the dignity of a man created in My image.
So God puts a mark on Cain that will serve as a sign to anyone who might come against him that this man - yes, this man; this sinner, this murderer - belongs to God.
The New Testament tells us that nothing can separate us from the love of Christ, not even our sin (for which He already died); this mark of grace on creation's first murderer proves it.