T. Austin-Sparks emphasizes the critical need for spiritual sight in his sermon 'The Man Whose Eye Is Opened', illustrating how spiritual blindness is a pervasive issue affecting both the world and the church. He references biblical accounts of individuals like Balaam and Saul of Tarsus, who were blinded by personal gain and zeal, respectively, to highlight the dangers of spiritual blindness. Sparks argues that true spiritual sight is a miraculous work of God, essential for understanding divine truth and purpose. He calls for believers to seek a deeper revelation from God, asserting that the church needs individuals who can confidently proclaim, 'I was blind, but now I see.' Ultimately, he stresses that spiritual authority comes from having one's eyes opened to the truth of God.