We can say that true gratitude does not give rise to the debtor's ethic because it gives rise to faith in future grace. With true gratitude there is such a delight in the worth of God's past grace, that we are driven on to experience more and more of it in the future. . . it is done by transforming gratitude into faith as it turns from contemplating the pleasures of past grace and starts contemplating the promises of the future.
A determination to succeed is the only way to succeed that I know anything about.