"Two things are required for reformation in our church and the transformation of our society.
First, the gospel. This comes when people stop trusting in any and every form of law-keeping, discipleship or whatever they want to call it, as a means of establishing peace or fellowship with God. As we have seen [in Luke 10:25-28], Christ's demands for salvation-by-discipleship are so high that only the most self-deluded soul would attempt it. But having been saved by Christ's discipleship, death, and resurrection alone, we do enter that high calling of discipleship ourselves. So first we need the gospel, to truly bring us into a right relationship with God. Apart from the gospel, the law can only condemn, oppress, and threaten.
But once we are justified by grace apart from obedience, that same grace gives us the power to live a new life - not a perfect life, but a new life. What we need, then, is a recovery of the greatness of God's law, first, to cut our foolish pride off at the pass and cause us to despair of our own efforts at pleasing God, and then, second, to remind us of what true discipleship really is once we become God's children by His free adoption.
For both our justification and our sanctification we desperately need to recover God's idea of holiness, His standard for right relationships, because, quite frankly, it seems to bear only slight resemblance to the personal and social piety of evangelicals in America today."
Michael Horton, The Law of Perfect Freedom, p. 173