In this series of beautifully crafted sermons, first delivered to the congregation of Boston's historic Park Street Church in 1937, Harold John Ockenga invites his listeners—then and now—to embrace the kind of historic Christianity that challenges the mind, transforms the behavior, and warms the heart. Calling Christianity "a religion of the heart" first and foremost, he explores the biblical foundations and practical implications of the religious heart, the wicked heart, the pricked heart, the contrite heart, the believing heart, the hardened heart, the burning heart, the pure heart, the troubled heart, and the loving heart.