In this sermon, Pastor Kevin Smith explores John 14:15-24, focusing on how the Holy Spirit helps believers experience their spiritual union with Christ and the loving presence of God. He compares Christians to deep-sea divers who need oxygen from their natural world to survive in water - similarly, believers need the Holy Spirit as their life source to survive in this foreign world. The sermon emphasizes that through the indwelling of the Holy Spirit, Christians are spiritually united with Christ, experiencing His resurrection life and power.