There are three main points that Leithart attempts to demonstrate in this text: “Baptism” is Baptism, “The Body of Christ” is the Body of Christ, and Apostasy Happens.
Leithart argues that all of the references to baptism in the New Testament are references to actual water baptism. Arguments to the contrary are groundless. They necessitate an arbitrary distinction between “water baptism” and “spirit baptism” which is absent from the text. Others argue for such a union between sign and signified that one can refer to the “sign” while intending that which is signified as the referent. As Leithart rightly points out, this approach is unwarranted and becomes an easy escape for any who deny sacramental efficacy to argue that any text about the effect of baptism is just playing word games and doesn’t mean what it says. Especially illuminating and provocative is Leithart’s argument that baptism is not a sign, nor is it a means of grace. Rather, it is a rite.
The second argument of Leithart is that the “body of Christ” is the body of Christ. In this chapter, Leithart proposes that the internal/external approach to the New Covenant and the visible/invisible church distinction are not valid Biblical categories. The phrase “body of Christ” is a reference to all who are in the corporate social community of the church. Thus, Leithart proposes that a better distinction would be between the historical and eschatological church. Though all in the visible community partake of Christ in some manner, not all of these people will share in the eschatological kingdom due to lack of faith.
Finally, Leithart argues that apostasy happens. In contradiction to the commonly understood definition of the Perseverance of the Saints, Leithart argues that one can have a true relationship with Christ and subsequently be cut off. He convincingly demonstrates that typical Calvinistic interpretations of falling away passages are unconvincing. Leithart does not, however, abandon the concept of predestination. According to Leithart, God does predestine the elect unto salvation and even predestines the apostasy of those who fall away.
Being a Lutheran myself, I had minor disagreements with Leithart’s presentation; namely his insistence on double predestination and adoption of certain New Perspective on Paul views that I find unpersuasive. That being said, this is one of the best presentations of the doctrine of baptism I have read. Even if one disagrees, this book will cause one to think further through the issues and challenge common assumptions.
Peter J Leithart’s “The Baptized Body” is a fascinating read. Coming from the controversial “Federal Vision” movement, Leithart seeks to infuse a high sacramental theology into Reformed Christianity. His argument comes primarily through exegesis, though with a strong dose of Calvin references. Leithart argues that contemporary Reformed Christianity has deviated from both the Biblical and Calvin’s understanding of baptism.