Thomas Brooks emphasizes that diseases, aches, and pains are consequences of sin, and failing to recognize this connection only exacerbates one's suffering. He explains that while grace does not eliminate human nature, it enhances our sensitivity to God's discipline, allowing us to feel the weight of our burdens without losing faith. Brooks illustrates this with examples of faithful figures who, despite their pain, maintained a spirit of gratitude rather than grumbling. He warns that indifference to God's afflictions can provoke further suffering, urging believers to acknowledge their struggles while trusting in God's purpose.