John Nelson Darby addresses W. Kelly regarding the doctrine of transubstantiation, arguing that it misrepresents the nature of Christ's sacrifice and redemption. He emphasizes that the true understanding of the Lord's Supper is rooted in recognizing Christ's broken body and shed blood as a representation of His death, rather than a literal presence in the elements. Darby asserts that the Roman Catholic interpretation undermines the essence of redemption and the significance of Christ's sacrifice, which is central to the faith. He critiques the modern origins of this doctrine and highlights the importance of understanding the spiritual truth behind the symbols used in communion. Ultimately, he encourages a faith that rejoices in the reality of a glorified Christ, rather than a dead one.