What follows is an overview of the facts at hand:

History of Church Incorporation

In order to understand exactly why The Free Church Movement is necessary, we must first obtain a clear overview of how government incorporation has evolved in the history of the Christian Church.

Here's what The Catholic Church's official Encyclopedia has to say about the ancient history of Church incorporation:

"Civil Incorporation of Church Property

Christianity at its very beginning found the concept of the corporation well developed under Roman law and widely and variously organized in Roman society. It was a concept that the early Christians soon adapted to their organization and, as a means of protection in the periods of persecution. Whether we attach to the burial corporations (collegia tenuiorum or funeraticia) of the early Christians the importance that De Rossi and other archæologists do, there can be no doubt that in the second and third centuries of the Christian era the corporation was generally resorted to as a means of holding, and transmitting church property. In later times this concept fitted in naturally with the genius of the religious orders, and the great monastic establishments of the Middle Ages were organized on that plan. "In the Middle Ages, all life", says Dr. Shahan (Middle Ages, p. 346), "was corporate. As religion was largely carried on by the corporations of monks and friars, so the civic life and its duties were everywhere in the hands of corporations." The mortmain legislation of the Middle Ages indicates that the corporation, as adapted for the holding of ecclesiastical property, was not only a secure, but a prosperous method of tenure in times of feudal warfare." 

To emphasize that the corporation was, first and foremost, an instrument valued because of the role it plays in the survival of physical things, Justice Strong, formerly of the United States Supreme Court, noted that arguments about property were what caused questions of religion to most often find their way to court: "Almost all, if not all, the questions mooted in the civil courts of this country, relating to church polity, discipline, officers or members, have arisen incidentally in controversies respecting church property" (Relation of Civil Law to Church Polity, p. 40)."

It is recognized in numerous decisions of American courts (Am. and Eng. Ency. of Law, XXIV, 330), that the terms "church" and "incorporated religious society" are not identical. The former is the larger term — its objects and purposes are moral and religious, the church corporation is subsidiary, having to do chiefly with the care and control of the temporalities.

"...control of temporalities" is a fancy way of saying "control of worldly things."  Now anyone who has ever read much Bible knows Scripture teaches that connecting the Church to worldly things is problematic at best and absolutely disastrous at worst.

Disaster aptly describes the ministry of the Church of Jesus Christ in this generation in the United States of America.  Before anyone noticed, the government of the USA ejected Jesus Christ and His law from the affairs of State, nation and people.  Now that God's people have begun to notice, the role that the corporation rules have played in conditioning the churches to collaborate with evil is obvious to those who have eyes that see.