Charles Finney emphasizes the critical importance of self-examination in understanding one's true character in the faith, urging believers to actively assess their moral standing before God. He outlines the necessity of this requirement for personal peace, honesty in faith, and effective service to others, arguing that uncertainty about one's spiritual state hinders both personal growth and outreach. Finney asserts that self-examination is not only possible but essential, providing practical steps for believers to engage in this process, including focusing on the realities of sin, their relationship with God, and their feelings towards others. He warns against the dangers of self-deception and encourages believers to actively engage with their faith and the world around them to gain clarity about their spiritual condition.