Flavel designed this devotional treatise to aid all professing Christians in exploring their
faith and cleansing their lives of sin. He takes his inspiration from Proverbs 4:23, which
reads: “Keep your heart with all vigilance, for from it flow the springs of life.” Flavel
explains that “keeping the heart” means not only keeping it away from evil, but also
keeping it as one keeps a garden, nurturing it. Just as a gardener must plant according
to the seasons, so also must one keep the heart in different ways across the seasons of
human life. In the latter half of his treatise, Flavel offers advice for doing just that.