The central message of this sermon is that God's nature and identity are the most important things about us, and that our understanding of God has a direct impact on our lives. The sermon highlights how humanity's natural tendency is to distort or deny God's true nature due to sin and idolatry, but also shows how God progressively reveals Himself as the Supreme God who is unique and alone. Through various biblical examples, the speaker demonstrates how God's people have struggled with worshiping false idols and gods, but ultimately, they come to realize that there is only one true God. The sermon concludes by introducing Jesus Christ, who claims to be God incarnate, which presents a profound challenge to humanity's understanding of God's nature. Ultimately, the sermon aims to emphasize the importance of having a correct understanding of God's identity and nature, which has far-reaching implications for our lives and relationships with Him.