The original Greek language of the Apostles’ and Nicene creeds describes the Church as “catholic” (small c), which means “universal.” It declares that there is only one Christian Church on earth. As early as the 1400’s, however, “Christian Church” was commonly used and understood to mean the same as “catholic.”
After the Reformation, the Church of Rome more intentionally used “Catholic” (capital C) to distinguish itself as the true Church over against Protestants. Over time, that usage began to function as a denominational title. It then made even more sense for Lutherans to use “Christian,” since we are part of the catholic Church, but clearly not the Catholic Church.
Only in 1978, when the Lutheran Book of Worship (green hymnal) was published, did we switch back to using “catholic Church” in the creeds. The reasons for the change were not all clear, but it became crystal clear through the next 35 years of trying to clarify (small-c) catholic from (capital-c) Catholic that it was endlessly confusing. Despite its original meaning, people assume that “catholic” (capitalized or not) refers to the Roman Catholic Church and are often baffled when Lutherans confess their faith in “the holy catholic Church.”
So, to clarify our confession—to ourselves and especially to guests—we have reclaimed the word Lutherans consistently used in all but the last generation, confessing our faith in “the holy Christian Church.” The meaning is the same, but we hope this communicates it more clearly.