In this opening sermon from The Seasons of Keeping the Heart, Proverbs 4:23 records a wise father, Solomon, impressing upon his son the sacred, lifelong responsibility of guarding the heart. This great work, commanded by God, is to be pursued with active and ongoing vigilance, for from the heart flows all of life. The sermon calls believers to take up this essential labor of the inner life, for the purity of the heart shapes every season of the Christian journey.