The central message of this sermon is that Jesus Christ is not just a teacher or a guide, but the very embodiment of life and resurrection. He is not just offering a way to eternal life, but he himself is the source of life. The speaker emphasizes that Christianity is not a philosophy or a set of rules, but a personal relationship with God through Jesus Christ. This relationship is based on faith in Jesus' person and work, rather than our own efforts or behavior. As such, it changes everything, including our understanding of accountability, morality, and the meaning of life. The speaker argues that if there is no resurrection, then life has no ultimate significance, and we would be free to live however we please with no consequences. But because Jesus teaches us about a future where we will give an account to God for our lives, it means that our actions have eternal implications, and we should live in light of this reality.