Thomas Brooks emphasizes the distinction between external and internal duties of religion, noting that many Christians, as well as hypocrites, often focus on outward practices like attending church and participating in rituals, while neglecting the deeper, inward spiritual responsibilities. He highlights the importance of self-examination, self-resignation, and divine meditation as essential components of true faith. Brooks calls believers to engage in these inward duties to cultivate a genuine relationship with God and to apply the truths of Christ to their own lives.