Theses on Communion Fellowship with Those Who Believe Differently
The true visible church in an absolute sense, or part of the same, is that church in which the Word of God is preached purely and the Holy Sacraments are administered according to Christ’s institution.
A Fellowship in which the Word of God is fundamentally denied, or in which a fundamental denial of the Word of God is tolerated, is not a true orthodox church, but a false heterodox church or sect.
Every man is obligated to recognize the true visible church, and, if he has the opportunity to join it.
Every man is obligated to avoid heterodox churches, and in the event that he has belonged to a heterodox church, his obligation is to renounce it and separate himself from it.
True Christians are also found in heterodox fellowships as a result of their lack of knowledge.
Those who are aware of the partial apostasy of the church fellowship to which they belong and yet continue to remain within that fellowship are not to be considered among the weak but are either the lukewarm whom the Lord will spit out of his mouth or Epicurean religious skeptics who within their hearts would ask with Pilate, “What is truth?”
The main purpose of the Holy Sacrament is to be a tool and a means through which the promises of grace are offered, communicated, and appropriated, as with a seal, guarantee, and pledge through which these promises are confirmed. However, within this major purpose, as a secondary goal, the Sacrament is to be a distinguishing sign of confession and a bond of fellowship in worship.
Therefore Communion fellowship is Church fellowship.
Holy Communion was not instituted to make people Christians. It was instituted to strengthen the faith of those who already are true Christians. Therefore Communion should be administered to no one who has been revealed as a false Christian.
In Holy Communion the Body and Blood of Christ is actually present, distributed and received by every communicant. Therefore Communion can not be administered to anyone who does not confess a belief in this mystery without grievous sin.
Holy Communion is a mark of confession of Faith and Doctrine among those who celebrate together. Therefore the admission of members of heterodox fellowships to the celebration of communion within the Lutheran Church is in conflict with:
1. Christ’s institution;
2. The commanded unity of the church in faith and accordingly in confession;
3. Our love for those to whom the Sacrament is administered;
4. Our love for our own fellow believers, especially the weak who by this action would be given serious offense.
5. The command not to become participants in the sin and error of others.
We do not place members of heterodox fellowships under excommunication or declare them to be heretics or damned by our refusal to allow them to participate in the celebration of communion within the fellowship of the Lutheran Church. Instead, they are merely suspended until such time as by their separation from the false fellowship they are reconciled with the orthodox church.
The heterodox themselves regard and declare it improper for them to commune with those who are orthodox. Would it not then be disgraceful for those who are last in regard to Christ’s own institution and administration of the Sacrament to expose those who have been first?
The more unionism and syncretism is the sin and corruption of our time, the more the loyalty of the orthodox church now demands that the Lord’s Supper not be misused as a means of external union without internal unity of faith.
Source (with explanations of each thesis): http://holytrinitylc.com/WaltherCommunionTheses.pdf