In this sermon, the preacher emphasizes the importance of having a heart that is perfect toward God. He uses the story of Elijah and the captain of fifty to illustrate how God shows himself strong on behalf of those whose hearts are perfect toward him. The preacher also references 1 John 3:20-22, where it is stated that if our hearts do not condemn us, we can have confidence toward God and receive answers to our prayers. The sermon concludes with a reminder that the eyes of the Lord are searching throughout the earth for those whose hearts are perfect toward him, and that the effectual fervent prayer of a righteous person avails much.