In this sermon, the preacher begins by discussing the gathering of sinners and the consequences they face. He uses the example of the rebellion of Korah and his followers, who were swallowed up by the earth as punishment for their defiance. The preacher then shifts focus to a greater gathering that is happening every day, where God is gathering his enemies to ultimately destroy them. He compares this gathering to a huntsman surrounding his prey, emphasizing the divine power and justice at play. The sermon concludes by discussing the gathering of souls in the afterlife, where sinners await judgment before the ultimate judge.

William Gurnall preaches about the strengthening power of sincerity in a Christian's spirit, emphasizing how sincerity acts as a girdle that fortifies the believer in their spiritual journey. He highlights that sincerity not only covers our weaknesses but also establishes and strengthens the soul for the Christian warfare, contrasting it with the weakening and unsettling nature of hypocrisy. Gurnall explains that sincerity provides preserving strength to keep the soul pure in the face of temptation, recovering strength to help the fallen rise again, and comforting strength to lift the believer above the waves of troubles. He urges the audience to assess their hearts for sincerity, to seek God's grace for more sincerity, and to trust in God's provision and promises for their spiritual journey.