In distinguishing Evangelical dogmatics from liberal Protestantism on the one hand, and Roman Catholicism on the other, Barth spends a great deal of time focusing on the issue of proclamation and the role in plays in the life of the church. Here seems to be one of the central points at which Barth’s ecclesiology differs from and challenges Catholic ecclesiology and, more generally, any supremely sacramental ecclesiology.
In speaking of (and commending) the Reformers’ break with Rome, Barth argues that
Proclamation of the basis of the promise which has been laid once for all, and therefore proclamation in the form of symbolic action [the sacrament], had to be and to remain essential for them [the Reformers]. But this proclamation presupposes that the other [preaching], namely, repetition of the biblical promise, is taking place. The former must exist for the sake of the latter, and therefore the sacrament for the sake of preaching, not vice versa. (CD1/1, p. 70)
This seems to be one of the key issues for understanding Barth’s ecclesiology in contrast to Roman Catholicism and other strongly eucharistic traditions. For Barth the nature of grace as God’s “unfathomably free act” (p. 68) requires us to find the church’s “center” not in any act which the church possesses or hands on as if “there flows forth from Jesus Christ a steady and unbroken stream or influence of divine-human being on His people” (p. 68). Any such unbroken continuity between God’s free grace and the being of the church is to be rejected in Barth’s thought. There can be no embracing the idea of the sacrament as a “causare, continere el conferre gratiam” (causing, containing, and conferring grace, p. 69) in that the relationship between divine grace and human response cannot be one of cause and effect, but of “the Word and faith.”
Thus, at the heart of Barth’s claim here is an insistence that the church does not possess or cause grace through its own actions, even the sacraments. Rather the church’s “center” must be the proclamation of the Gospel through which God, thought the Holy Spirit brings people to faith in the event of hearing the Word. As such Barth’s ecclesiology (at least here) is strongly informed by a theology of the missio dei. The church exists by virtue of its being the passive recipient of God’s missional entrance into the world in Christ, which the church then proclaims as an act of obedience. What Barth offers is a missional ecclesiology centered on the ek-centric movement of God’s Word which the church hears and proclaims to the world rather than a sacramental eccesiology centered on the church’s mediation of grace to itself.