So the question for all churches is "Do you believe the NT pattern of church structure was God's pattern?" If so, then men corrupted that pattern shortly after it was instituted (regardless of motive).
In the Acts we find the apostles making a pragmatic decision to create the diakonate, deacons, in order to help split the duties in an organized way.
There's nothing in the text that presents this as an act Divine will, it is a pragmatic decision. No where does Christ, for example, establish the office of deacon, no where does God command it, no where do the Apostles suggest it came by the inspiration of the Holy Spirit. It was a human decision.
So question: Was the creation of the diakonate a corruption of God's pattern of church governance?
If no, then we must admit that the structure of Church governance is not strictly a matter of God ordaining a specific pattern to be followed to the letter, but a matter of human organization for the sake of good order and to ensure the continued operation of the Church for the sake of the Gospel.
Arguing that episcopacy is a corruption is fundamentally no different than saying the diakonate is a corruption. The only difference between that the latter is mentioned specifically as happening early on in the Church's lifetime, while a developed episkopate just a little later. That is if one is arguing that human structures are innately a corruption of Divine structure.
Instead this is what I see in the New Testament:
1) Christ appoints His apostles and sends them out.
2) The apostles going forth established churches, and with that came the need for pastors to act in the apostles' stead as shepherds of Christ's flock.
3) As the first century progressed these apostle-appointed pastors became differentiated as the churches grew and need arose; to accommodate that need a differentiation between a house pastor and a regional pastor came to be. Presbyters served the immediate needs of each individual congregation, with bishops serving as pastors of a group of individual congregations.
This isn't a corruption of the "NT pattern" since if we go strictly by Scripture there is no established "pattern". Scripture offers no strict outline of how to "do" Church polity, it merely describes the situation(s) at different points in the Church's early history, from the Acts recounting the beginning of the Church in the 30s, Paul's letters up and through the mid 60s, some of the catholic epistles for the remainder of the 1st century. No proscribed hard outline ever appears in the New Testament texts because none of the books of the New Testament ever set out to do this, they are written with assumed circumstances and situations, which are evolving within the period of their writing.
Things have clearly evolved from when we first see the disciples huddled together in the upper room on Pentecost and by the time the Pauline pastoral epistles were written. Such changes in how the Church operates are seen within the New Testament itself, and unless we want to charge the pastoral epistles as "corruption" then we have to admit that such changes are perfectly reasonable and acceptable.
The problem with Primitivism, which is what you are advocating, is two-fold:
1) Primitivism claims to seek a return to a "pure" New Testament Christianity, but in reality will only read backward into the New Testament the anachronistic opinions of modern people.
2) The first century Church and the twenty-first century Church are never going to be the same thing. Just like both are never going to look like the twelfth century Church. These are moments in the Church's history which were unique because of culture, language, political climate, and all those unique historical factors that we simply are not going to be able to replicate. The best that could ever happen with such a pursuit is a shallow facade, a cheap imitation. Like a poorly done Civil War battle reenactment.
Every attempt toward Primitivism has resulted in nothing more than the creation of a new denomination based on the limited, fallible opinions of its founder thinking he or she has reinvented the wheel. The problem is that their new wheel is a poorly constructed square.
I assure you, the wheel works, the wheel ain't broke.
-CryptoLutheran