If grace is the essence of theology, then as Berkouwer said, gratitude must be the essence of ethics.
John Wesley once declared that if we took grace too seriously, especially the doctrine of election, it would undermine our only basis for pursuing a holy life – fear of punishment and hope of rewards. But isn’t that a selfish motivation for the Christian life? That’s always been the fear – “Too much grace! It’ll throw a wrench in the whole process of Christian growth.”
But the Scriptures insist that a legalistic view of the Christian life is what leads us right back to fear and bondage. Since the Law, though good, in and of itself can never give us the power to perform what it commands, the gospel not only reconciles us to God in the first place, it’s the only fuel we have to keep us going in the process of sanctification. Therefore, gratitude – not fear of punishment or hope of rewards – is the only proper basis for pursuing a holy and God-glorifying existence.
If our salvation depended upon us for one moment, even in the slightest degree, we would eventually either become self-righteous, pretending that we were actually pulling it off, or we would despair of ever knowing whether God really accepted us. How could we possibly love God and serve our neighbor freely if we were still caught up in the saving of our own skin?
(Michael Horton, Guilt, Grace & Gratitude)