T. Austin-Sparks emphasizes the profound truth that Christ, who descended and ascended, is destined to fill all things with His presence and character. He explores the necessity of emptying ourselves of self-fulness to make room for Christ's fullness, illustrating this through biblical figures like Abraham, Jacob, and Moses, who underwent significant emptying processes to fulfill God's purpose. Sparks highlights that this emptying is not merely negative but a divine law leading to greater spiritual capacity and fruitfulness. The sermon calls believers to recognize the importance of a crisis moment in their lives where they surrender self-life for Christ-life, ultimately leading to a glorious climax in God's eternal plan. The message encourages a deeper understanding of suffering and trials as part of God's work to enlarge our capacity for His fullness.