God is able to use ordinary people to turn back the tide of evil, as seen in the lives of David, Elijah, Hezekiah, Esther, and Nehemiah. Through their accounts, we see that despite obstacles, we don't need to buckle under overwhelming evil but can stand firm in God's power. Their stories illustrate themes in the great controversy between God and Satan, such as God challenging the power of darkness, His working in human hearts, defeating those who challenge Him, and the need for prayer and repentance when conflicts arise.