I expected The Fourth Cup to be an extension of the fourth section of Jesus and the Jewish Roots of the Eucharist by Brant Pitre. Indeed, Pitre wrote the introduction for The Fourth Cup, and Hahn for Pitre’s book. Likewise, Jewish Roots (Which looks toward Hebrew types of the Christian ) address several Church-taught types of the Eucharist from the Old Testament, and presents the consummation of the “Fourth Cup” of a Passover Seder (on the Cross) as a potential additional one.
Those are addressed. But not thoroughly or at depth. Rather, The Fourth Cup is primarily the story of a Reformed preacher converting to the Catholic religion. Hahn talks more about covenant theology than any Catholic writer I’m familiar with. While Taylor Marshall does not go into his own story as much in The Crucified Rabbi, the thrust of the narrative is similar: an attempt to follow the Christ’s actions in their culture context (whether liturgical for Hahn, or ecclesial-legal for Marshall) leads to — at the least — an approximation of Catholic practice.
As Hahn descries his own story, and attempts to move his church’s liturgy to follow the model of Jesus, Hahn increasing understands the question to be that either a general apostasy occurred very early on, or the Christian liturgical model is the Catholic-Orthodox liturgical model. Han does not address to follow-on questions: could a general apostasy have happened (the assumption of Mormonism) or the Apostolic forms are best kept in the Eastern Orthodox communions.
Hahn is a fantastic writer. While I generally learned more from The Jewish Roots of the Eucharist, the words I remember clearest are Hahn’s from the introduction. Likewise, when the trial of Jesus is mentioned, Shaneyfelt’s Trial of Jesus Christ is the superior book and better reconstructive history. But Hahn’s turns of phrase are the ones that stay with you.
I read The Fourth Cup in the Audible edition.