The sermon centres on the call to 'keep thy heart with all diligence,' presenting the heart as both precious ground and a spiritual battleground. Rooted in Proverbs 4:23, it emphasizes the heart's eternal significance, its role as the source of life and moral living, and its need for divine renewal through Christ. The preacher underlines that the heart, though naturally deceitful and prone to wander, is the battleground where the Christian must wage constant warfare against internal and external enemies: particularly the devil's schemes and the world's allurements. Through vivid imagery drawn from John Bunyan's Holy War and practical exhortations, the message calls for vigilant self-examination, guarding the senses (ear, eye, mouth, feet), and deliberate obedience to Scripture. Ultimately, the encouragement is grounded in God's promise to sustain His people, inviting believers to guard their hearts with unwavering diligence, knowing that their eternal destiny depends on it. 1. Precious ground 2. Battle ground