Bertha Smith emphasizes the significance of the sacrificial system in the Old Testament, particularly the role of the priests and the offerings they made, which foreshadowed the ultimate sacrifice of Jesus Christ. She explains how the priests had to be cleansed and dedicated before they could serve God, highlighting that only those who have died to sin and are cleansed can truly dedicate themselves to the Lord. Smith stresses that one cannot dedicate sin to a holy God and that true dedication involves a complete surrender of oneself to Christ. The sermon illustrates the importance of understanding the holiness of God and the cost of sin, urging believers to recognize their need for Christ's sacrifice and to live in a way that honors Him. Ultimately, she calls for a deeper awareness of God's holiness and the necessity of being cleansed to serve Him effectively.