In this sermon, the preacher focuses on John 3:16 and the love of God. He emphasizes that God's love is perfect and can cast out fear, which is prevalent in the world today. The preacher uses the analogy of an explorer trying to measure the depth of the ocean to illustrate the unfathomable depth of God's love. He also highlights that God's love is unmerited and undeserved, and gives an example of a man sacrificing his life for his friends to demonstrate the depth of God's love. Overall, the sermon emphasizes the incredible and incomprehensible nature of God's love.