A translation from the FAQ page of Luther Foundation Finland.
Why do you not leave the Evangelical Lutheran Church of Finland if it is so bad?
It is the duty of Christians to abide in the vine by remaining in God’s word:
“I am the true vine, and my Father is the vinedresser. Every branch in me that does not bear fruit he takes away, and every branch that does bear fruit he prunes, that it may bear more fruit. Already you are clean because of the word that I have spoken to you. Abide in me, and I in you. As the branch cannot bear fruit by itself, unless it abides in the vine, neither can you, unless you abide in me. I am the vine; you are the branches. Whoever abides in me and I in him, he it is that bears much fruit, for apart from me you can do nothing. If anyone does not abide in me he is thrown away like a branch and withers; and the branches are gathered, thrown into the fire, and burned. If you abide in me, and my words abide in you, ask whatever you wish, and it will be done for you.” (John 15:1–7)
Christ Himself creates and sustains the Church with His word and sacraments. People can neither found nor sustain the Church with their own decisions or mutual contracts. That is why abiding in the vine becomes the central issue in Jesus’ parable — but not the only one. According to Jesus, abiding in the vine is remaining in His word. By His word, God prunes and cleanses His Church.
On this basis, the Lutheran Reformers did not imagine they could leave the Church and to start a new one, as if the Church was for them to found. Instead, by their teaching and practical actions they exhorted Christian to remain in God’s word and to work for the renewal of the Church of their time in order to remove unbiblical human inventions and abuses. The Catholic church reacted to this Reformatory programme with force, by driving out the shepherds and congregations who had adopted the Reformation, complete with excommunication and anathemas.
For a long time now, revival movements and organisations have been operating within the Evangelical Lutheran Church of Finland, which have worked for the renewal and building up our church on the Lutheran basis described above. In the midst of this church, God has given us a new birth in Holy Baptism, and it is there that He has been calling us again and again to repentance and renewal, both as individuals and as a community. Luther Foundation Finland and the people involved in it have never wanted anything other than to remain in God’s word and in the Lutheran Confessions (the Book of Concord), which rightly interpret the Scriptures; and they have wanted to live out this their faith both as individuals and as a community. Luther Foundation wants to promote the creation of worshipping communities which aim to orient themselves and to strive according to the seven marks of the Church, which the Reformer, Martin Luther, sets out in his book, On the Councils and the Church (1539).
When we read the Reformer’s description of the seven marks of the Church, it is readily apparent that our church has not stepped off the road they mark only in the question of the Office of the Ministry. The question of the status of God’s word in its various dimensions has brought about a ??? conflict and wound into our church. The leadership of our church has cared for us, their sheep, by encouraging us to step aside if we have problems. We have done that. Now that the conflict has come to a head, it encourages us to leave the church. Is this the voice of a good shepherd or of a general manager?
In 1541, Luther justified the position of the evangelical congregations and their relationship with the Catholic church in these words:
“Nobody can deny that we have in fullness and purity the preaching office and the word of God, that we teach and preach diligently, without adding any new, sectarian, or human doctrine, and in this we do just as Christ commanded and as the apostles and all of Christendom have done. We invent nothing new, but hold and remain true to the ancient word of God, as the ancient church had it. Therefore we are, together with the ancient church, the one true church, which teaches and believes the one word of God. So the papists once more slander Christ himself, the apostles, and all of Christendom when they call us innovators and heretics. For they find nothing in us but what belongs to the ancient church—that we are like it, and are one church with it.”