John Gill emphasizes the significance of maintaining a good conscience, which is transformed through the sanctification of the Spirit and the blood of Jesus. He explains that a good conscience leads to a life that reflects the teachings of the Gospel, requiring both internal faith and external profession. Gill highlights that despite being falsely accused by others, a humble and sincere demeanor can lead to shame for those who speak ill of believers. Ultimately, living according to a good conscience serves to defend and recommend the doctrines of the Gospel.