1. Our Lord has created one church. Jesus refers to it as “my church.” In speaking to Peter, He said, “And I say also unto thee, That thou art Peter, and upon this rock I will build my church, and the gates of hell shall not prevail against it” (Matt. 16:18). All true believers in Christ belong to this one church (Ephesians 2:19-22). We give expression to our faith in this church in the Apostles’ Creed: “I believe in the Holy Ghost, the Holy Christian Church, the communion of saints,”
2. This church is found where the Word of God is proclaimed and the Sacraments are rightly administered. It is through these means that the Holy Ghost builds this church. We have assurance that the Word will not return void but that it will accomplish that which God pleases. (cf. Isaiah 55:11.)
3. God has given to the church (believers) the authority to preach the Gospel and administer the Sacraments. This is known as the Office of the Keys. Believers have the authority to exercise the keys individually and collectively. (John 20:21-23 and I Peter 2:9)
4. It is God’s will “that Christians unite in order to preserve the means of grace pure and unadulterated, to use these means of grace for their own edification, to show the unity that exists among them, and to join hands in bringing the good news of salvation in Christ to others. Jeremiah 23:28; John 8:31-32; Acts 2:42; Psalm 133:1; Matthew 28:19-20,” (ELS Catechism question 247, p. 146-47)
This normally is done through the external forms of the local congregation, synod and denomination. Although it is God’s will that Christians gather for public worship, these external forms, as such, however, are not divinely instituted. “The kingdom of God cometh not with observation.” (Luke 17:20) Luther correctly says, “there is not a single letter in holy Scripture saying that such a church (i.e. a ‘physical, external Christendom’), where it is by itself, is instituted by God … If they can show me that a single letter of Scripture speaks of it, I will recant my words.” (LW 39, 70)
The local congregation is the primary grouping because this is where Christians live and where they can readily and practically carry out the commands of God on a regular basis.
5. The authority in the church is the Word of God. When the Word is spoken by an individual, a local congregation, synod, or denomination, it is as valid as if the Lord himself spoke it from heaven. “He that heareth you heareth me.” (Luke 10:16)
6. “As those who love God and want to remain true to His Word, we must see to it that we remain members of the true Church by sincere faith in Christ as our Savior; that we adhere to the congregation, synod, or denomination which teaches the Word of God in all its purity; that we do all in our power to maintain, promote, and extend God’s Kingdom and work by prayer, personal service and financial support; and that we avoid all false churches and all other denominations that profess a religion which is false. II Cor. 13:5; II Cor. 12:15; Matt 7:15; 1 John 4: 1; Romans 16:17; II Cor. 6:14.” (ELS Catechism Question 249, p. 147-148)
7. So far as the relationship among the various external groupings is concerned, Christians will be governed by the law of love and will want to do things decently and in order. In external matters we uphold the autonomy of the local congregation; also the advisory capacity of synod to the congregations, as asserted in our synodical constitution. (Ch. 5, Par. 4) This is the practice of the Evangelical Lutheran Synod.