"Notice how God is both kind and severe. He is severe toward those who disobeyed, but kind to you if you continue to trust in his kindness. But if you stop trusting, you also will be cut off."
I love Tom Wright's comments on this passage. They're so practical.
Some people imagine God to be always severe, always cross, always ready to find fault. Such people urgently need to discover just how gracious God has been in Jesus the Messiah, and how this grace is theirs for the asking.
But other people sometimes imagine that God is simply kind and generous in a sense which would rule out his ever rebuking or warning anyone about anything. Such people urgently need to discover just how much God hates evil in all its destructive and damaging ways, and how firmly he confronts, and ultimately rejects, those who persist in perpetuating it.
–Paul for Everyone; Romans Part Two