"Secret Power; or, The Secret of Success in Christian Life and Work" by D. L. Moody is a religious treatise likely written in the late 19th century. The book discusses the spiritual power that derives from the Holy Spirit, emphasizing the importance of divine guidance and the believer's relationship with God in achieving success in their Christian life and outreach. Moody aims to inspire readers to actively seek and utilize this power to fulfill their mission as Christians. The opening of the book establishes the focus on the Holy Spirit as the source of true spiritual power and efficacy in a believer's life. Moody reflects on the necessity of divine quickening and inspiration, asserting that the Holy Spirit is essential for effective witness and work in the Christian faith. He emphasizes that without this power, efforts become meaningless and burdensome, while with it, each task is transformed into a joyous service for God. Through a series of scriptural references and personal reflections, the opening portion lays the groundwork for a deeper exploration of the Holy Spirit's role in empowering Christian life and service. (This is an automatically generated summary.)