C.H. Spurgeon emphasizes the necessity of wholeheartedness in both secular and spiritual endeavors, asserting that true prosperity comes from diligent and passionate work. He argues that God rewards those who labor earnestly, whether in business or in their service to Christ, and that half-hearted efforts lead to failure. Spurgeon highlights that the most effective Christians are those who approach their tasks with zeal and commitment, mirroring the earnestness of Jesus, who exemplified true heart-work. He challenges believers to reflect on their dedication and to serve their Master with the same fervor that Jesus displayed. Ultimately, Spurgeon calls for a revival of passion in the Christian life, urging believers to avoid lukewarmness.