The sermon focused on the vital keys to effective prayer, emphasizing obedience, brokenness, persistence, and praying down the will of God. Obedience involves aligning with God's Word, while brokenness is about having a heart for others, especially the lost. Persistence in prayer is crucial as it deals with spiritual warfare across heaven, hell, and earth. The sermon highlighted the importance of praying specifically and believing in God's will, using biblical examples to illustrate these points.