John L. Dagg, in his excellent book Manual of Church Order, writes the following:

In our definition of a church, we have called it an assembly of believers in Christ.  This definition tells what a church is according to the revealed will of God, and not what it becomes by the criminal negligence of its ministers and members, or the wicked craft of hypocritical men who gain admittance into it.  When we study the Word of God to ascertain what a church is, we must receive the perfect pattern as presented in the uncorrupted precepts of that word, and not as marred by human error and crime.

Later, Dagg adds:

Churches are often criminally careless, both in the reception of members, and in the discipline of them when received.  If the piety of churches were very fervent, men of cold hearts could not remain happy among them, and could not continue to have their true character concealed.

– John L. Dagg, Manual of Church Order (Harrisonburg, VA: Gano Books, 1990), 80, 99.

If indeed we have been “criminally negligent” in our churches, should not the solemn words of our elder brother be calling us to repentance?