T. Austin-Sparks explores the profound concept of 'mystery' as presented in Ephesians, emphasizing that while God's will was once hidden, it is now revealed through Christ and the Church. He explains that true understanding of this mystery requires divine illumination, as mere knowledge does not lead to spiritual growth. Sparks highlights the dual nature of the mystery: the incarnation of Christ and the spiritual body of the Church, which embodies God's presence. He stresses that spiritual enlargement comes through a deeper revelation of Christ within the community of believers, rather than in isolation. Ultimately, he calls for Christians to seek a higher spiritual position through unity and relatedness with one another.