Karl Barth's rejection of infant baptism is as infamous as it is controversial. Opponents of Barth's doctrine of baptism have defended infant baptism with the historical, covenantal and sacramental arguments, with Oscar Cullmann's Baptism in the New Testament being among the best representatives of these arguments. George Hunsinger recommended to me in a personal correspondence, W. Travis McMaken's book, The Sign of the Gospel: Toward an Evangelical Doctrine of Infant Baptism after Karl Barth as a post-Barthian solution for affirming infant baptism.
In The Sign of the Gospel, Dr. McMaken begins by assuming that Karl Barth's critique of infant baptism was correct and forges a new path for affirming infant baptism by using Barth against Barth, and therefore he goes through Karl Barth to a new and surprising solution to this ancient debate. McMaken's post-Barthian solution for affirming infant baptism may best be introduced in the following quotation from The Sign of the Gospel:
By way of recapitulation, perhaps the best way to describe my understanding in this volume is with reference to a quotation by Eberhard Jüngel. He claims that Barth's 'doctrine of baptism is . . . not an appendix to the Church Dogmatics, but rather . . . a test-case' such that anyone who 'wants infant baptism should not seek nourishment for the pulpit from Barth's doctrine of election. . . . It is one or the other—one must decide for oneself.' This volume has sought to demonstrate the former aspect of Jüngel's declaration while controverting the second. In other words, it defends two claims.
First, it demonstrates that Barth's doctrine of baptism in CD IV/4, and his rejection of infant baptism in particular, is not a final aberration of his theology but is deeply consistent with his mature theological commitments.
Second, it argues that Barth's theological commitments do not necessarily terminate in this fashion; that is, it is possible to advance a doctrine of baptism that is both consistent with Barth's mature theology and affirms infant baptism as a fitting form of baptismal administration.
McMaken, W. Travis, The Sign of the Gospel: Toward an Evangelical Doctrine of Infant Baptism after Karl Barth, Minneapolis: Fortress, 2013. pg275, Print. (formatting slightly modified)
I am surprised and impressed by The Sign of the Gospel because this book thoroughly defends the Barthian doctrine of baptism, and then moves through it and onward to a post-Barthian doctrine of infant baptism. McMaken demonstrates that there has been a superficial rejection of Karl Barth's arguments against infant baptism, as if the CD IV/4 fragment was only an appendix, rather than a test-case (as the previous quotation described). He has also shown that Markus Barth's works rejecting infant baptism were unjustly ignored or rejected in the same way that Barth's CD IV/4 fragment has been dismissed. (Markus Barth is Karl Barth's eldest son and accomplished theologian).
The Sign of the Gospel also contains excursuses explaining Karl Barth's rejection of the traditional prooftexts for infant baptism, and helpful explanations of Karl Barth's negative assessment of the sacramental and covenantal arguments based on these texts. Instead of these traditional prooftexts, McMaken points to the Great Commission in Matthew 28:18-20 as the post-Barthian scriptural foundation for infant baptism. The Sign of the Gospel was able to explain Karl Barth's scriptural criticism in a way that I did not fully understand the first time I had read Karl Barth's CD IV/4 fragment on baptism. McMaken also demonstrates an excellent ecumenical stance on the doctrine of baptism, where those whom do not administer infant baptism and those whom do, may recognize each other's baptism. Also, I love that this book is titled, The Sign of the Gospel, which is from Calvin's commentary on the Great Commission in Calvin's commentary on the harmony of the gospels. The following second and longer quotation is a helpful overview of the arguments presented so far in The Sign of the Gospel:
I have endeavored in this chapter to construct a doctrine of baptism on the soil of Barth's mature theology where infant baptism is a legitimate form of the gospel proclamation by which the church discharges its missionary task. Although the decision for or against infant baptism must be a contextual one made by each church in its particular time and place, it is an inherently fitting mode of baptismal administration. To make this case, I undertook a reconfiguration of Barth's doctrine of baptism founded on critically assessing how he conceived of baptism's basis. By dismissing Barth's historical conjecture concerning Christian baptism's origin, and recovering the importance of Matthew 28:18-20 on Barthian grounds, I argued that baptism is best understood as a mode of gospel proclamation whereby the church discharges its missionary task, which exists in a close and mutually implicating relation with the church's instructional mode of the gospel proclamation. Jesus' baptism by John retains importance at this point insofar as it provides baptism's content, as well as its dimension of depth in Jesus Christ's saving history. With reference to baptism's goal, I argued that water baptism's primary goal is Spirit baptism and that it is thereby implicated in a stratified multiplicity of goals. The saving history of Jesus Christ grounds this relic complex, extending to the active discipleship of individual human beings that necessarily results from the Spirit's awakening work. I also argued here that the holistic particularity or objective-subjective character of water baptism when conceived as a mode of the church's gospel proclamation helps to make sense of the ethical force with which baptism is deployed in the New Testament. In terms of baptism's meaning, I argued four points.
First, Barth conceives of witness as the mode of the church's mediation, and he believes that the church's mediating witness is given a share in Jesus Christ's self-mediating self-witness in the event of awakening to conversion or, alternatively, Spirit baptism.
Second, how Barth conceives of this participation by the church's witness in Jesus Christ's self-witness is not accurately described by notions of parallel activity or of instrumentality; rather, Barth's far more radical conception of the relation between divine and human activity proposes their paradoxical identity. He arrives at this conception by rejecting the sort of causal thinking that depends on an analogia causalis between divine and human action. Instead of God simply extending his causality through the church's instrumentality or parallel with its activity, Jesus Christ himself encounters particular human beings in and as the church's proclamation.
Third, I understood to reread Barth's doctrine of baptism in order to demonstrate that such a position is not foreign to Church Dogmatics IV/4.
Fourth and finally, I argued that identifying that church's baptismal gospel proclamation as fundamentally an event of epiclesis allows for the church to administer baptism in confident and expectant hope that its prayer for the baptizand's Spirit baptism will be fulfilled, even though the church cannot say how or when that fulfillment will occur.
The doctrine of baptism that I have advanced is open to infant baptism insofar as I have argued that infant baptism is a fitting form of baptismal administration. This mirrors the New Testament witness in neither requiring nor forbidding the practice. Reading Barth against Barth, I argued that the most responsible theological position with reference to the New Testament witness requires that the church make a decision in every time and place concerning whether the baptism of infants is a proper application of the baptismal mode of its gospel proclamation undertaken in service to its missionary task. Further I argued that infant baptism practiced on the bias of the doctrine of baptism I advanced here avoids many of the dangers against which Barth warns.
McMaken, W. Travis, The Sign of the Gospel: Toward an Evangelical Doctrine of Infant Baptism after Karl Barth, Minneapolis: Fortress, 2013. pg273-274, Print. (formatting slightly modified)