C.H. Spurgeon emphasizes the divine command to preach the gospel, starting at Jerusalem, as instructed by Jesus. He highlights the importance of preaching repentance and remission of sins, asserting that true repentance is a profound change of heart that leads to a genuine turning away from sin. Spurgeon encourages believers to begin their witness at home and among those who may oppose them, reminding them that the greatest sinners are often the first to receive God's mercy. He calls for a faithful proclamation of the gospel, emphasizing that it is not only a duty but a privilege to share the message of salvation in Christ's name.