A.B. Simpson emphasizes the necessity of supernatural power and direction in Christian service, asserting that our works are not our own but are prepared by God through the Holy Spirit. He illustrates that true effectiveness in ministry comes from dying to self-reliance and receiving divine empowerment, as exemplified by biblical figures like Moses and Paul. Simpson warns against the dangers of acting on personal impulse rather than waiting for God's guidance, highlighting the importance of aligning with His divine plan. He concludes that even the smallest acts of service, when done in the Spirit's strength, can yield significant results for God's kingdom. Ultimately, he calls believers to seek God's specific purpose for their lives to avoid wasted efforts.