T. Austin-Sparks emphasizes in his sermon 'Life Triumphant Over Death' that John 6 reveals the profound truth of life overcoming death through Christ, who is the Bread of Life. He highlights the importance of union with Christ, where believers must continuously feed on Him to maintain a testimony of life. The sermon underscores that this feeding involves prayer, the Word, fellowship, and worship, which are essential for spiritual sustenance and victory over death. Sparks encourages believers to recognize that life in Christ is not a one-time event but a daily practice that leads to a continuous testimony of triumph. Ultimately, he asserts that the Lord desires His followers to embody this truth of life triumphant over death in their lives.