A.B. Simpson emphasizes the call to 'Enlarge the place of thy tent,' urging believers to attempt and expect great things from God. He reflects on the humble beginnings of the missionary movement and the need for expansion in faith, love, and service to reach the lost. Simpson highlights the importance of strengthening the core of the church through God's Word, personal holiness, and a spirit of self-sacrifice. He reminds the congregation that God, as our Maker and Husband, provides infinite resources for this mission. The sermon serves as a powerful reminder of the ongoing call to evangelize and serve in humility and faith.