There is no question but that the essence of holiness is love. Paul in the Epistle to the Romans says that ‘love is the fulfilling of the law’ (13:10). We only conceive of holiness truly when we conceive of it in terms of love. . . . The holiness of the man who is in Christ, the holiness of the Christian, is not some mechanical conformity to the law, neither is it mere morality. A man may be moral without loving holiness. Morality is a negative quality. It means not committing sin. But that is not holiness. Holiness is positive, it is essentially a matter of loving. The Christian is a man who loves holiness and he appears before God because he is ‘holy in love.’ He ‘hungers and thirsts after righteousness,; he delights in the law of God. He does not obey it as a task; he says with John in his First Epistle, chapter 5 verse 5: ‘His commandments are not grievous.’ That constitutes one of the best tests as to whether we are Christian or not. Do we enjoy Christian living? do we wish to be more Christ-like day by day? These are tests, and they are tests of love. The law of God really calls us to love. . . . (Mark 12:28-31).
D. Martyn Lloyd-Jones, God’s Ultimate Purpose: An Exposition of Ephesians One (Grand Rapids: Baker, 1978), 98-100.
If Lloyd-Jones is correct, as I think he is, several things follow. One is that moralism is a grave danger. It is a false substitute for holiness that can lure one into thinking he is right with God when he is not simply because he avoids certain sins or conforms his behavior to the Ten Commandments and other moral principles from Scripture. Another is that moralism is not solved by stepping away from the law, loosening its expectations, or forbidding its application beyond the bare letter to the real circumstances of our everyday lives. The true opposite of moralism is not antinomianism or license but holiness. In truth, the moralist and the saint may look much alike on the outside because both may have their eye on the same law. But the one acts mechanically, as Lloyd-Jones says, and the other acts out of love toward God and others.