Since we have been delivered from our misery by grace through Christ without any merit of our own, why then should we do good works?

Because Christ, having redeemed us by his blood, is also restoring us by his Spirit into his image, so that with our whole lives we may show that we are thankful to God for his benefits, so that he may be praised through us, so that we may be assured of our faith by its fruits, and so that by our godly living our neighbors may be won over to Christ.