The Ev. Lutheran Church is the total of all unreservedly confessing agreement with the pure Word of God,
of the teaching brought again to light through Luther’s reformation
and delivered summarily in writing to Kaiser and Reich at Augsburg in 1530
and repeated and expanded in the other so-called Lutheran symbols . . .
The Ev. Lutheran Church is sure that the teaching contained in its Symbols is the pure God’s truth
because it agrees with the written Word of God in all points . . .
The Ev. Lutheran Church rejects all fraternal and churchly fellowship
with those who reject its Confessions in whole or in part . . .
The Ev. Lutheran Church has thus all the essential marks of the true visible Church of God on earth
as they are found in no other known communion,
and therefore it needs no reformation in doctrine.
Following Luther and Walther, the Lutheran Church—Missouri Synod (LCMS) from its beginning rejected “all fraternal and churchly fellowship with those who reject its Confessions in whole or in part” because such rejection was a rejection of some truth taught by “the written Word of God.” The primary proof text for the termination of fellowship is Romans 16:17 (“watch out for those who cause divisions and create obstacles contrary to the doctrine that you have been taught; avoid them”).
This does not justify refusing to pray with anyone outside of one’s own church body, which may have been a legalistic way the doctrine of church fellowship has been applied in the past. The doctrine itself is sound: do not have fellowship with those who cause divisions contrary to what you have been taught (Romans 16:17). That is not talking about a weak believer who is not causing divisions and who is willing to believe everything in Scripture but who, out of ignorance, is led astray by false teaching. It is talking about those who stubbornly persist in supporting false doctrine even after admonishments against it. The Wisconsin Evangelical Lutheran Synod (WELS) makes that distinction clear in its Theses on Church Fellowship.
A change occurred in the LCMS doctrine of church fellowship in the first half of the twentieth century, culminating in the breakup of the Synodical Conference in 1963, as Mark E. Braun documented in A Tale of Two Synods: Events that Led to the Split between Wisconsin and Missouri. The change in the doctrine and practice of church fellowship is related to interpreting and applying Romans 16:17 and related texts of Scripture.
The Concordia Cyclopedia (Concordia Publishing House, 1927, “Unionism,” 774-775) explains the LCMS’s original doctrine in more detail:
Religious unionism consists in joint worship and work of those not united in doctrine. Its essence is an agreement to disagree. In effect, it denies the doctrine of the clearness of Scripture. It would treat certain doctrines as fundamental or essential and others as non-essential to Christian unity . . . A Christian who believes that God has clearly spoken through the prophets and apostles and through the Lord Jesus Christ cannot be a unionist. The indifferent and pacifist stand of the unionist is condemned in all those text which bid us beware of false prophets and to separate from those who deny the truth.
The texts cited as proof are Titus 1:13-14; 1 Timothy 2:12; 6:3-5,14; 2 Timothy 3:5; Matthew 7:15; Jeremiah 23:28; Acts 20:29; Romans 16:17; 1 John 4:1; 2 John 10:11. The “Unionism” entry continues,
In the light of these texts all joint ecclesiastical efforts for religious work (missionary, educational, etc.) and particularly joint worship and mixed (promiscuous) prayer among those who confess the truth and those who deny any part of it, is sinful unionism. If we hold to the doctrine of the clearness of Scripture, such compromise of the truth cannot be tolerated, nor can it be defended by the plea that religious differences, after all, rest upon misunderstanding.
Thus, full doctrinal unity is required for all forms of fellowship, including not only sharing in communion (“altar fellowship”) and in preaching (“pulpit fellowship”) but also for prayer fellowship and joint ecclesiastical work. Indeed, Romans 16:17 and similar Scriptures do not distinguish between the different categories of fellowship.
By contrast, at least since the adoption of the report “Theology of Fellowship” in 1967, the LCMS has officially distinguished between altar/pulpit fellowship on one hand and prayer/work fellowship on the other hand. According to the report, the doctrinal agreement needed for altar and pulpit fellowship is not necessary for joint prayers:
Our Synod should understand that, in the case of doctrinal discussions carried on with a view to achieving doctrinal unity, Christians not only may but should join in fervent prayer that God would guide and bless the discussions, trusting in Christ’s promise Matt. 18:19: “Again, I say unto you, that if two of you shall agree on earth as touching any thing that they shall ask, it shall be done for them of My Father which is in heaven.”
Such joint prayers, however, are expressions of Christian fellowship according to the Scriptures. Christian prayer is fellowship with the triune God. All those in fellowship with the Father and the Son are necessarily and without exception in fellowship with each other (1 John 1:6). Thus, for Christians to confess fellowship with that God in joint prayer while denying fellowship with each another is to confess something that is impossible according to Scripture. Since there is no distinction between joint prayer and prayer fellowship, there can be no basis for denying pulpit or altar fellowship whenever joint prayer is warranted. By the same token, whenever altar/pulpit fellowship is not warranted because of persistent false teaching, joint prayer (prayer fellowship) is not warranted either (Romans 16:17).
Church fellowship takes place not only in teaching, communion, and prayer, but also when churches carry out their other work together. That is the teaching of Scripture, as explained in the Theses on Church Fellowship of the WELS.
Striking examples of fellowship in church work without true doctrinal unity involve relief organizations in North America. The LCMS, consistent with her adopted report quoted above but contrary to her original doctrine, participates in Lutheran World Relief, joint with the Evangelical Lutheran Church in America (ELCA). Similarly, the Lutheran Church—Canada (LCC) works jointly with the Evangelical Lutheran Church in Canada (ELCIC) via Canadian Lutheran World Relief. The mission/values statements of these relief organizations make it evident that the joint work is not only corporation in non-ecclesiastical matters but is performed on the basis of a shared faith:
Many of the pervasive doctrinal errors of the ELCA and the ELCIC, some of which undermine the foundations of the Christian faith, have been known for decades.
In conclusion, the current fellowship doctrine and practices of the LCMS are substantial and long-standing departures from the original doctrine and practice of the synod. Worse, the teaching and practice of the LCMS and the LCC are contrary to what Scripture says about Christian fellowship and the termination of such fellowship when necessary (Romans 16:17).
What should Christians do if they have strayed into the LCMS, the LCC, or another church body that persists in teaching error in spite of patient admonitions? According to the LCMS’s Brief Statement (1932, Section 28), leaving a church body that causes doctrinal divisions contrary to the Holy Scriptures they have been taught is commanded in Romans 16:17: “watch out for those who cause divisions and create obstacles contrary to the doctrine that you have been taught; avoid them”:
Since God ordained that His Word only, without the admixture of human doctrine, be taught and believed in the Christian Church, 1 Pet. 4:11; John 8:31, 32; 1 Tim. 6:3, 4, all Christians are required by God to discriminate between orthodox and heterodox church-bodies, Matt. 7:15, to have church-fellowship only with orthodox church-bodies, and, in case they have strayed into heterodox church-bodies, to leave them, Rom. 16:17. We repudiate unionism, that is, church-fellowship with the adherents of false doctrine, as disobedience to God’s command, as causing divisions in the Church, Rom. 16:17; 2 John 9, 10, and involving the constant danger of losing the Word of God entirely, 2 Ti. 2:17-21.