Church Conflict: Johann Gerhard and Augustine

An interesting distinction between absolute and fundamental unity in the Church Triumphant and Church Militant. The question is what are the fundamentals of unity?

http://cyberbrethren.com/2009/10/22/why-is-there-strife-and-conflict-in-the-church/

Johann Gerhard offers these thoughts:

(7) We must also add that the unity of faith and doctrine in the Church in this life is not perfect nor absolute in all parts, for at times among the members of the true Church controversies occur which tear apart that holy unity. Therefore a distinction must be made between an absolute unity, perfect and free of all dissent, which will first take place in the church triumphant, and a fundamental unity which consists of agreement over the principal articles, though controversies may arise over some less principal parts of the faith or about indifferent ceremonies or even about the interpretation of some passages of Scripture. This is the sort of unity that takes place in the church militant, for in it we never find such a harmony but that it is mixed with some disagreements. For in this life “we know in part and we prophesy in part” (1 Cor. 13:9).

Augustine, De civ. Dei, bk. 15, c. 5:

"Good people and good people, if they are perfect, cannot fight among themselves. Those who make progress but are not yet perfect can do so, as every good man fights another to the degree in which he fights against himself. In every man “the flesh lusts against the Spirit, and the Spirit against the flesh.” Therefore spiritual concupiscence can fight against the carnal concupiscence of another, or carnal concupiscence can fight against the spiritual concupiscence of another in the same way as good and evil people fight with each other; or certain carnal lusts of two good but not yet perfect people fight among themselves in the same way as bad people fight with bad people. This goes on until the health of those being cured is brought to final victory."

Here Augustine is disclosing the cause of discords in the church. The truly devout have not yet been renewed perfectly. Rather, some remnants of the flesh remain in them. Therefore they do not attain the exact and perfect knowledge of the mysteries of faith. In some matters they dream and stagger. In the reborn, the flesh still battles against the Spirit. Therefore it can happen easily, especially at the suggestion of the devil, that those who indulge in the opinions of the flesh stir up contentions in the church. Yet unless stubbornness is added and unless the foundation of faith is removed, they are not immediately separated from the body of the Church because of that.