On the Love of God (Vol. 1) by St. Francis de Sales is a classic spiritual work that explores the nature of God's love and how the human soul responds to it. It explores the fundamentals of divine love, the soul's longing for God, and the process of becoming one with His will, making it a profound guide to Christian spiritual growth. It aims to guide readers toward a more devout life through a gentle and compassionate approach. This first volume lays a deep theological and mystical foundation for the loving relationship between God and humanity.