John Flavel was a preacher of the gospel at Dartmouth in Devon throughout the oppressive reign of Charles II. This treatise is based on Proverbs 4:23. It is pastoral in nature, with a view to rooting out hypocrisy among professing christians. Originally subtitled ‘A Saint Indeed’ Flavel writes earnestly of the essential need of a heart religion, and the practical demonstration of spiritual life in the soul.