17. Now you have the reason why the apostles Paul and Peter everywhere so faithfully enforce this virtue, the unity of the Spirit. It is the most necessary and beautiful grace that Christians possess. It holds together the Christian community, preventing factions and schisms, as before explained. So Paul here admonishes men to be careful for harmony, making every endeavor to preserve it. The term "unity of the Spirit" is used to make plain the apostle's meaning. He would thus emphasize oneness of doctrine—the one true faith. Since the Holy Spirit is present only where there is knowledge of and faith in the Gospel of Christ, "unity of the Spirit" implies a unity of faith. Above all things, then, the effort must be to preserve, in the Church, the doctrine of the Scriptures, pure and in its unity.
18. One of the wickedest offenses possible to commit against the Church is the stirring up of doctrinal discord and division, a thing the devil encourages to the utmost. This sin usually has its rise with certain haughty, conceited, self-seeking leaders who desire peculiar distinction for themselves and strive for personal honor and glory. They harmonize with none and would think themselves disgraced were they not honored as superior and more learned individuals than their fellows, a distinction they do not merit. They will give honor to no one, even when they have to recognize the superiority of his gifts over their own. In their envy, anger, hatred and vengefulness, they seek occasion to create factions and to draw people to themselves. Therefore Paul exhorts first to the necessary virtue of love, having which men will be enabled to exercise humility, patience and forbearance toward one another.
19. The character of the evils resulting to the Church from divisions and discords in doctrine is evident from the facts. Many are deceived; the masses immediately respond to new doctrine brilliantly presented in specious words by presumptuous individuals thirsting for fame. More than that, many weak but well-meaning ones fall to doubting, uncertain where to stand or with whom to hold. Consequently men reject and blaspheme the Christian doctrine and seek occasion to dispute it. Many become reckless pleasure-lovers, disregarding all religion and ignoring the Word of God. Further, even they who are called Christians come to have hard feelings against one another, and, figuratively, bite and devour in their hate and envy. Consequently their love grows cold and faith is extinguished.
20. Of so much disturbance in the Church, and of the resulting injuries to souls, are guilty those conceited, factious leaders who do not adhere to the true doctrine, preserving the unity of the Spirit, but seek to institute something new for the sake of advancing their own ideas and their own honor, or gratifying their revenge. They thus bring upon themselves damnation infinitely more intolerable than others suffer. Christians, then, should be careful to give no occasion for division or discord, but to be diligent, as Paul here admonishes, to preserve unity. And this is not an easy thing to do, for among Christians occasions frequently arise provoking self-will, anger and hatred. The devil is always at hand to stir and blow the flame of discord. Let Christians take heed they do not give place to the promptings of the devil and of the flesh. They must strive against them, submitting to all suffering, and performing all demands, whether honor, property, physical welfare or life itself be involved, in the effort to prevent, so far as in them lies, any disturbance of the unity of doctrine, of faith and of Spirit.
"There is one body, and one Spirit, even as also ye were called in one hope of your calling; one Lord, one faith, one baptism, one God and Father of all."
21. Christians should feel bound to maintain the unity of the Spirit, since they are all members of one body and partakers of the same spiritual blessings. They have the same priceless treasures—one God and Father in heaven, one Lord and Savior, one Word, baptism and faith; in short, one and the same salvation, a blessing common to all whereof one has as much as another, and cannot obtain more. What occasion, then, for divisions or for further seeking?
22. Here Paul teaches what the true Christian Church is and how it may be identified. There is not more than one Church, or people of God, one earth. This one Church has one faith, one baptism, one confession of God the Father and of Jesus Christ. Its members faithfully hold, and abide by, these common truths. Every one desiring to be saved and to come to God must be incorporated into this Church, outside of which no one will be saved.
23. Unity of the Church does not consist in similarity of outward form of government, likeness of Law, tradition and ecclesiastical customs, as the Pope and his followers claim. They would exclude from the Church all not obedient to them in these outward things, though members of the one faith, one baptism, and so on. The Church is termed "one holy, catholic or Christian Church," because it represents one plain, pure Gospel doctrine, and an outward confession thereof, always and everywhere, regardless of dissimilarity of physical life, or of outward ordinances, customs and ceremonies.
24. But they are not members of the true Church of Christ who, instead of preserving unity of doctrine and oneness of Christian faith, cause divisions and offenses—as Paul says (Rom 16, 17)—by the human doctrines and self-appointed works for which they contend, imposing them upon all Christians as necessary. They are perverters and destroyers of the Church, as we have elsewhere frequently shown. The consolation of the true doctrine is ours, and we hold it in opposition to Popedom, which accuses us of having withdrawn from them, and so condemns us as apostates from the Church. They are, however, themselves the real apostates, persecuting the truth and destroying the unity of the Spirit under the name and title of the Church and of Christ. Therefore, according to the command of God, all men are under obligation to shun them and withdraw from them.