D.L. Moody emphasizes that the Word of God is the greatest weapon, likening it to the sword of the Spirit, which must be wielded with the guidance of the Holy Spirit. He recounts a conversation between a Christian and a skeptic, illustrating that persistence in sharing Scripture can lead to transformation, regardless of initial disbelief. Moody stresses that it is not our job to convince others of the Word's truth; rather, we are to faithfully deliver God's message. He highlights biblical examples, such as Gideon and Saul of Tarsus, to show that God often uses human instruments to accomplish His purposes. Ultimately, Moody encourages believers to be willing vessels for God to use in spreading His Word.