In Jeffrey Johnson's sermon "The Fundamentals," he emphasizes the core, essential truths of the Christian gospel that cannot be compromised. He begins by referencing 1 Corinthians 15:1-11, where Paul reminds the Corinthians of the gospel message: Christ's death, burial, and resurrection according to the Scriptures. Johnson stresses that Christianity is not just about being a good person or vaguely believing in Jesus, but involves specific, non-negotiable beliefs. These include Christ's incarnation, sinlessness, death, burial, and resurrection.

The sermon addresses the issue the Corinthian church faced, which was influenced by Gnostic thinking that downplayed the physical body, focusing only on the spiritual. This led some Corinthians to deny the resurrection of the dead, which Johnson points out is a fundamental error. He argues that if Christians deny the bodily resurrection, they deny the gospel itself, because Christ’s resurrection is the foundation of Christian hope.

Johnson further explains that faith in the gospel is not just a one-time event but an ongoing commitment. Believing in the essentials of the gospel—Christ's death and resurrection—saves initially and continues to sustain the believer. He emphasizes that faith is not something we generate ourselves but comes from hearing the Word of God. Johnson highlights the importance of maintaining this faith and warns that failing to do so renders one’s belief vain. True faith in Christ is the only way to salvation, and it is faith in the power of the gospel, not in human wisdom or strength, that gives life and hope.

The sermon concludes by reminding listeners that faith is not about self-confidence or human effort but trusting fully in Christ’s work on the cross and His resurrection. This is how believers are saved and stand in grace—through the power of Christ, not their own.