In January of this year, I wrote this post about the notion that Christ founded an invisible Church. What I say here presupposes familiarity with that post.
Some Protestants affirm that Christ founded a visible Church. The problem for their position, however, is that it is entirely indistinguishable from (and therefore identical to) the position that "the Church is invisible but some of its members [i.e. the presently embodied ones] are visible". Even those Protestants who explicitly affirm that the Church is invisible recognize that some of its members are visible. In this way, therefore, those Protestants who affirm that Christ founded a visible Church are affirming a position that is identical to that of those who affirm that Christ founded an invisible Church. The Protestants claiming that Christ founded a visible Church have simply shifted the word "visible" to modify the word 'Church', but the position itself is exactly the same. That is why I wrote in January:
Conceiving of the Church as invisible and non-institutional, while referring to it as visible, is simply gnosticism conjoined with semantic and conceptual confusion. Those who explicitly deny that Christ founded a visible Church are in a much better position to discover their gnosticism than are those who wrap up their gnosticism in sacramental (non-gnostic) language.
Sometimes the Protestants who claim that Christ founded a visible Church will respond to this objection by claiming that it is the assembly that is visible, not merely the embodied believers. But this answer merely pushes back the problem, in two ways. First, there are, they will admit, multiple assemblies. And yet, they claim, there is one visible Church. So one problem for their position is that it is indistinguishable from the position that "the Church is invisible but its assemblies are visible". Thus either they have no justification for claiming that Christ founded a visible Church, since there is in actuality only a plurality of assemblies, or the visible Church that Christ founded is only the original particular assembly, say, in Jerusalem.
Second, this position faces the following trilemma. The first horn of the trilemma results if the assembly is not an actual entity. If the assembly is not an actual entity, then the assembly cannot be visible, for what is not actual cannot be visible. Therefore, if the assembly is not an actual entity, then the Church per se is not visible. Now consider the second and third horns of the trilemma. If the assembly is an actual entity, then either it ceases to exist as soon as the believers disperse to their homes after the service is over, or not. If the latter, then nothing distinguishes an assembly from a mere plurality, and I have already explained here why treating a mere plurality as an actual entity commits what A.N. Whitehead rightly called the "fallacy of misplaced concreteness". But if an assembly comes into existence when the believers come together, and ceases to exist as soon as the believers disperse, then each Sunday, in the same building, a new visible Church comes into existence, and thus the visible Church is not the Church that Christ founded.
At this point the Protestant might wonder why the Catholic is not faced with these very same problems. The Catholic is not faced with these problems because for Catholics the visible Church is essentially unified (and thus preserved in being) not by its members being in close spatial proximity to one another, but by a hierarchy of persons: priests to a bishop, and bishops to a head bishop. St. Ignatius of Antioch (d. 107 AD) wrote: "Where the bishop is, there is the Church". For Catholics what makes the Church per se visible is not that it has visible members, but that it has a visible hierarchy. The Church is unified not like a heap of stones, which goes out of existence whenever the heap is dispersed, but as a living organic body, with a visible head. So long as the members are in communion with the visible head, they form one body, because the visible head is one. (If there were two visible heads, then there would be two bodies, for we cannot serve two [equal] masters – see here.) The major problem for the Protestant position here is that it is impossible to have the organic unity of a living body without a hierarchy and a unified visible head. Dwight Longenecker writes:
As a Protestant I was taught that the Church was invisible. That is, it consisted of all people everywhere who believed in Jesus, and that the true members of the Church were known to God alone. This is true, but there is more to it than that. Invisibility and visibility make up the fifth paired set of characteristics that mark the truly authoritative church.And that is often exactly what many Protestants do say (see here); such people are being consistent. What I am pointing out here in this post is that there is no middle position. There is no middle position between being Catholic, and believing that the Church per se is invisible.
The Church is made up of all people everywhere who trust in Christ. However, this characteristic alone is not satisfactory because human beings locked in the visible plane of reality also demand that the Church be visible. Even those who believe only in the invisible church belong to a particular church which they attend every Sunday. Those who believe only in the invisible church must conclude that the church they go to doesn’t really matter.