Wanting a “pure” church has been the desire from the beginning of the Anabaptist movement, in contrast with the idea that everyone is a “Christian”.
From “The Anabaptist Vision” by Harold Bender:
The world would not tolerate the practice of true Christian principles in society, and the church could not tolerate the practice of worldly ways among its membership. Hence, the only way out was separation ("Absonderung"), the gathering of true Christians into their own Christian society where Christ's way could and would be practiced. On this principle of separation Menno Simons says:
”All the evangelical scriptures teach us that the church of Christ was and is, in doctrine, life, and worship, a people separated from the world.”
In the great debate of 1532 at Zofingen, spokesmen of the Swiss Brethren said:
“The true church is separated from the world and is conformed to the nature of Christ. If a church is yet at one with the world we cannot recognize it is a true church.”
However, this vision is hardly helped when we have leaders who are not completely interested in leading in purity. Maybe we’d be more successful if we were described as below.
In Zwingli's last book against the Swiss Brethren (1527), for instance, the following is found:
“If you investigate their life and conduct, it seems at first contact irreproachable, pious, unassuming, attractive, yea, above this world. Even those who are inclined to be critical will say that their lives are excellent.”
Bullinger, himself, who wrote bitter diatribes against them, was compelled to admit of the early Swiss Brethren that
“Those who unite with them will by their ministers be received into their church by rebaptism and repentance and newness of life. They henceforth lead their lives under a semblance of a quite spiritual conduct. They denounce covetousness, pride, profanity, the lewd conversation and immorality of the world, drinking and gluttony. In short, their hypocrisy is great and manifold.”
...... As we review the vision of the Anabaptists, it becomes clear that there are two foci in this vision. The first focus relates to the essential nature of Christianity. Is Christianity primarily a matter of the reception of divine grace through a sacramental-sacerdotal institution (Roman Catholicism), is it chiefly enjoyment of the inner experience of the grace of God through faith in Christ (Lutheranism), or is it most of all the transformation of life through discipleship (Anabaptism )? The Anabaptists were neither institutionalists, mystics, nor pietists, for they laid the weight of their emphasis upon following Christ in life. To them it was unthinkable for one truly to be a Christian without creating a new life on divine principles both for himself and for all men who commit themselves to the Christian way.
The second focus relates to the church. For the Anabaptist, the church was neither an institution (Catholicism), nor the instrument of God for the proclamation of the divine Word (Lutheranism), nor a resource group for individual piety (Pietism). It was a brotherhood of love in which the fullness of the Christian life ideal is to be expressed.