"Who knows, God may turn and relent and withdraw His burning anger so that we will not perish."
When Jonah went and preached to the city of Nineveh, he preached one message - "Nineveh will be destroyed in 40 days." When the people of Nineveh heard it, they were immediately repentant. They were broken and contrite, and began to wear sackcloth, from the greatest to the least. Even the King got in the spirit, and he cast aside his royal garments and put on sackcloth and at in ashes. He commanded that everyone, even the animals, wear sackcloth, and said that maybe, just maybe, God would forgive them and turn aside his anger.
That's the right attitude. He never said, "We've repented, so God has to forgive us. Because we've done these things, we deserve to be forgiven." NO!!
See, we Christians sometimes get in this attitude of if we do this, then we can force God's hand to do that. We look at 2 Chronicles 7:14 with the wrong perspective, thinking that God will congratulate us for repentence, as if we some how earned the forgiveness. "Good job, you repented, now you're forgiven."
True repentence is about being contrite, about falling down on our faces in shame and humilty, saying "Father, I've sinned, and I'm no longer worthy to be called your son. Make me a servant and let me serve you." When we have that attitude, torn and haggard from our sins, then we're forgiven.