How do we know that Christ is our hope and joy?

The sermon reiterates that the Apostle Paul found his joy and hope in the people he ministered to because he saw them as a manifestation of God's salvation. In Christ, believers have the assurance of their salvation and a confident expectation of being presented blameless at His coming. This hope is rooted in the righteousness of Christ, which cannot be taken away. The joy derived from knowing one's standing before God in the righteousness of Christ is the fulcrum of a believer's spiritual life, emphasizing reliance and trust in Christ alone.