“Neither the Old Testament believer nor the Savior severed the law of God from His gracious person.
It was not legalism for Jesus to do everything His Father commanded Him. Nor is it for us.
In some ways the Marrow Controversy resolved itself into a theological version of the parable of the waiting father and his two sons. (Luke 15:11-32)
The antinomian prodigal when awakened was tempted to legalism: ‘I will go and be a slave in my father’s house and thus perhaps gain grace in his eyes.’
But he was bathed in his father’s grace and set free to live as an obedient son.
The legalistic older brother never tasted his father’s grace. Because of his legalism he had never been able to enjoy the privileges of the father’s house.
Between them stood the father offering free grace to both, without prior qualifications in either.
Had the older brother embraced his father, he would have found grace that would make every duty a delight and dissolve the hardness of his servile heart.
Had that been the case, his once antinomian brother would surely have felt free to come out to him as his father had done, and say:
‘Isn’t the grace we have been shown and given simply amazing? Let us forevermore live in obedience to every wish of our gracious father!’
And arm in arm they could have gone in to dance at the party, sons and brothers together, a glorious testimony to the father’s love.”
–Sinclair B. Ferguson, The Whole Christ: Legalism, Antinomianism, and Gospel Assurance—Why the Marrow Controversy Still Matters (Wheaton, IL: Crossway, 2016), 173-174.