Continuing with Barth

The catholicity of the church, by which is meant that which is general and comprehensive, the essence of which true church is recognized as true, is found only in the union of the church with her Head, Jesus Christ. Any church having a different essence—as in its ecclesiastical structure or doctrinal commitments—is not the true church. Catholicity, therefore, is not a matter of human wisdom, but is a matter of trust and is known by revelation. It is found in the real, essential connection between the body of Christ—the church—and the Head—Jesus.

The first three marks are given by revelation and understood by faith. This puts them beyond human reach and places them squarely in the purview of the Holy Spirit. The question is, how can we know whether a specific congregation bears the marks? Barth answers this question with apostolicity…but more on that later.