Richard Sibbes always sought to get under the superficial layer of his listeners' behavior and deal with their hearts. He knew that the outward acts of sin spring from the inner desires of the heart. Merely to alter a person's behavior without dealing with those desires would cultivate hypocrisy, the self-righteous cloak for a cold and vicious heart. Sibbes believed that hearts must be turned and evil desires eclipsed by stronger ones for Christ.
Josiah's Reformation is as relevant today as when it was first published in 1629. Our busyness and activism so easily degenerate into a hypocrisy in which we keep up all the appearance of holiness without the heart of it. Christians even use Christ as a package to pass on to others, instead of enjoying him first and foremost as their own Savior. But true reformation must begin in the heart, with love for Christ. And that can only come when the free grace of God in Christ Jesus is preached.