John Wesley emphasizes the necessity of working out one's own salvation, highlighting that while it is God who empowers us to will and act according to His good pleasure, we must actively engage in our salvation with earnestness and diligence. He explains that the truths of God's nature and the work of Christ were largely unknown to the ancient heathens, and it is through the Gospel that we gain understanding and the ability to pursue holiness. Wesley encourages believers to recognize their responsibility in the process of salvation, which involves both divine grace and human effort, urging them to act with fear and trembling as they seek to fulfill God's will.