In her sermon to high school students, Pastor Amanda discusses the Christian doctrine of the Trinity, described as God the Father, Son, and Holy Spirit. Using accessible analogies like the three states of water (solid, liquid, and gas), she explains the concept of three distinct persons existing as one God, emphasizing the importance of understanding and personal belief in this fundamental aspect of Christianity. She encourages students to explore and articulate their own beliefs about the Trinity, using scripture and personal reflection to make the doctrine relatable and significant in their daily lives. The interactive sermon aims to deepen students' faith and understanding of their relationship with God.