The concept of the visible and invisible church is a complex and misunderstood distinction in Christian theology. According to St. Augustine, the invisible church is made up of true believers who are substantially within the visible church, but may not be outwardly apparent due to the presence of unbelievers and hypocrites. The visible church is a mixed body of believers and unbelievers, and the task of the invisible church is to make itself visible through faith and good works.