On church fellowship and the distinction between orthodox and heterodox churches
God has revealed his heavenly doctrine clearly in his Word, the Holy Scriptures. The Holy Scriptures is so clear that it is the only source of doctrine and also the only norm by which we may judge every doctrine.
Although the unity of the true church of believers is founded on the common faith in Christ, this faith is not visible to us (Eph 4:1-6). The unity of the visible church is instead founded on unity in the doctrine that creates and preserves faith and the right administration of the sacraments (Matt 28:19-20, AC VII).
Orthodox and heterodox churches
We recognize that where the word of God is present, there will be Christians, also in heterodox church bodies. Because heterodoxy is a mixing of truth with error, therefore God forbids us to practice external fellowship with such Christians. (2 Thes. 3:14,15).
Because we are bound to the whole word of God (Acts 20:27) and commanded to reject all false teachers (Ro 16:17), we must insist upon complete unity with other churches, before we can recognize church fellowship with them.
This is stated in the FC Ep X, 7: We believe, teach, and confess also that no Church should condemn another because one has less or more external ceremonies not commanded by God than the other, if otherwise there is agreement among them in doctrine and all its articles, as also in the right use of the holy Sacraments, according to the well-known saying: Dissonantia ieiunii non dissolvit consonantiam fidei, Disagreement in fasting does not destroy agreement in faith.
The visible churches with whom church fellowship is either denied or recognized are the gatherings around word and sacrament, administered by the publicly called teachers and preachers. The doctrine which is to be judged is the public doctrine taught and practiced by the church, not the subjective faith nor the occasional errors of church members, as long as persistent errors are not tolerated by the church.
Church fellowship is to be broken as soon as it has been established that doctrinal unity no longer exists, since it is not based on the subjective faith or repentance of individuals or churches, but on their objective unity in doctrine.
Expression of church fellowship
Every joint worship is an expression of fellowship; but not every joint worship is an expression of church fellowship.
Church fellowship is expressed through fellowship in the means of grace and in the worship of the public gatherings around word and sacrament. Expression of church fellowship cannot be limited to the public gatherings of congregations. Joining together in other public, official or otherwise organized worship is an expression of church fellowship, since such public, official or organized worship belongs to the church. Such organized worship must be under the control of a properly called orthodox teacher.
A principal distinction must be made though between public expressions of fellowship with another church and its representatives on the one side and fellowship between individuals in the privacy of a home or family on the other side. Here we are not dealing with churches or organizations acting as churches.
We can pray with those whom we recognize as weak brethren, as long as this does not involve or can be seen as acceptance of error. On the other hand we must refuse to pray with persistent errorists or unrepentant sinners even in private since prayer is an expression of spiritual fellowship.
1. Those must be rejected who believe that Holy Scripture is not clear and sufficient and that we are therefore not bound to confess all the doctrines therein and to reject all teachings that are not in accordance with the revealed doctrine in Scripture.
2. Therefore, those must be rejected who think that compromises against the Word of God are allowed in order to win more souls. It is the pure teaching of the gospel and the right administration of the sacraments that creates and sustains faith.
3. Those theologians of glory must be rejected who believe that some amount of unionism or doctrinal compromise is allowable in order to have or keep a larger visible church.
4. Those must be rejected who do not distinguish in any way between the public doctrine of the church and its teachers and the subjective faith or private opinions of the hearers, and who therefore believe that church fellowship is declared to individuals and not to congregations and pastors.
5. Those must be rejected who see every gathering of Christians as being on the same level as the official gatherings of the church. Furthermore those are rejected who deny that the doctrine of church fellowship is to be applied also outside the public worship of the church.
6. Those must be rejected who believe that minor doctrinal errors are to be tolerated in the teaching of a church or in the fellowship of churches and that fellowship is to be recognized when there are only small doctrinal differences.
7. Those must be rejected who believe that only the official doctrinal position of a church needs to be correct and not the actual teaching, preaching and practice. Also those must be rejected who believe that a church can be seen as orthodox when it teaches and preaches correctly but tolerates its members openly attacking the true doctrine. On the other hand, we must also reject the opinion that we must ascertain adherence to the true doctrine by every individual member of another congregation.
8. Those must be rejected who believe that once doctrinal disunity has been recognized, church fellowship can still be upheld on the basis of the hope that the false teachers will repent. Those must be rejected who break fellowship when it has not yet been established that there is no longer doctrinal unity.
9. Those must be rejected who believe that public joint prayer can be practiced with representatives of heterodoxy. Those must also be rejected who believe that public or organized worship with the heterodox outside the local congregation is allowed.
10. Those must be rejected who believe that we can never pray in private with members of a heterodox church body. Those are to be rejected who believe that we can always pray in private with members of a heterodox but Christian church body.