(The following is an excerpt from a book by Edwin Hatch . Thanks to Jon Zens for connecting me to this great author. What I found very helpful was to realize that the troubles with "church-as-we-know-it" did not start with Constantine but can be traced back even earlier, to the 2nd Century.)
It is impossible for any one, whether he be a student of history or no, to fail to notice the difference and contrast between the Sermon on the Mount and the Nicene Creed.
The Sermon on the Mount is the promulgation of a new law of conduct; it
assumes beliefs rather than formulates them; the theological
conceptions which underlie it belong to the ethical rather than the
speculative side of theology; metaphysics are totally absent.The Nicene Creed is a statement partly of historical facts and partly of dogmatic inferences; the metaphysical terms which it contains would probably have been unintelligible to the first disciples; ethics have no place in it. The one belongs to a world of Syrian peasants, the other to a world of Greek philosophers.
[Why] an ethical sermon stood out in the forefront of the teaching of Jesus Christ, and a metaphysical creed in the forefront of the Christianity of the fourth century, is a problem which claims investigation… I will ask you to note the broad distinction which exists between what in the primitive churches was know as "prophesying" and that which in subsequent times came to be know as "preaching".
The prophet was not merely a preacher but a spontaneous preacher. He preached because he could not help it, because their was a divine breath breathing within him which must needs find an utterance. It is in this sense that the prophets of the early churches were preachers. They were not church officers appointed to discharge certain functions. They were the possessors of a charisma, a divine gift which was not official but personal. "No prophecy ever came by the will of man; but men spoke from God, being moved by the Holy Spirit." They did not practice beforehand how or what they should say; for "the Holy Ghost taught them in that very hour what they should say." They were ignorant of the rules both of style and of dialectic.
In the course of the 2nd Century, this original spontaneity of utterance died almost entirely away. It may almost be said to have died a violent death.
The dominant parties in the Church set their faces against it. The survivals of it in Asia Minor were formally condemned. The Montanists, as they were called, who tried to fan the lingering sparks of it into a flame, are ranked among heretics. And Tertullian is not even now admitted into the calendar of the saints, because he believed the Montanists to be right…
Prophesying died when the Catholic Church was formed. In the place of prophesying came preaching.
We consequently find that with the growth of organization there grew up also, not only a fusion of teaching and exhortation, but also the gradual restriction of the liberty of addressing the community to the official class.
It was this fusion of teaching and exhortation that constituted the essence of the homily: its form came from the sophists. It was not only natural but inevitable that when men who had been trained in rhetorical methods came to make addresses, they should follow the methods to which they were accustomed. It is probable that Origen is not only the earliest example whose writings have come down to us, but also one of the earliest who took into the Christian communities these methods of the schools.
When the Christian communities emerge into the clearer light of the 4th century, the influence of the rhetorical schools upon them begins to be visible on a large scale and with permanent effects. The voice of the prophet had ceased, and the voice of the preachers had begun…
No sooner is any new impulse given either to philosophy or to religion than there arises a class of men who copy the form without the substance, and try to make the echo of the past sound like the voice of the present. So has it been with Christianity. It came into the educated world in the simple dress of a Prophet of Righteousness. It won that world by the stern reality of its life, by the subtle bonds of brotherhood, by its divine message of consolation and of hope.
Around it thronged the race of eloquent talkers who persuaded it to change its dress and to assimilate its language to their own. It seemed thereby to win a speedier and completer victory. But it purchased conquest at the price of reality. With that its progress stopped. There has been an element of sophistry in it ever since; and so far as in any age that element has dominated, so far has the progress of Christianity been arrested. Its progress is arrested now, because many of its preachers live in an unreal world. The truths they set forth are truths of utterance rather than truths of their lives. But if Christianity is to be again the power that it was in its earliest ages, it must renounce its costly purchase.
The hope of Christianity is, that the class which was artificially created may ultimately disappear; and that the sophistical element in Christian preaching will melt, as a transient mist, before the preaching of the prophets of the ages to come, who, like the prophets of the ages that are long gone by, will speak only “as the Spirit gives them utterance.”