A rant placed here mainly for my own benefit:
Like attracts like, right? So if you are wanting to reach Transylvanian lumberjacks with the gospel, the most effective way to do it is to start a church for Transylvanian lumberjacks. After all, there are plenty of parachurch organisations that operate on this principle and they seem to have a fruitful ministry in reaching their particular group. So this ministry tactic is naturally transferable to churches?
No! In this instance we can not allow ourselves to be guided by pragmatism. This is a danger we must be on our guard against because it is a denial of the gospel. The church is the place that welcomes everyone: Jew and Greek, slave and free, male and female, the rich, the socially excluded, even the Transylvanian lumberjack. But the vision of the New Testament is that they are welcomed into God's church together:
"May the God of endurance and encouragement grant you to live in such harmony with one another, in accord with Christ Jesus, that together you may with one voice glorify the God and Father of our Lord Jesus Christ. Therefore welcome one another as Christ has welcomed you, for the glory of God. For I tell you that Christ became a servant to the circumcised to show God's truthfulness, in order to confirm the promises given to the patriarchs, and in order that the Gentiles might glorify God for his mercy. As it is written, 'Therefore I will praise you among the Gentiles, and sing to your name.'" Romans 15. 5-9
"This mystery is that the Gentiles are fellow heirs, members of the same body, and partakers of the promise in Christ Jesus through the gospel." Ephesians 3.6
As the church proclaims Jesus, the Holy Spirit brings different types of people together to form the church, God's new humanity (cf. Ephesians 2.11 ff.). Churches modelled on the homogenous unit principle deny this reality. And yet God uses this reality to declare to the world the wisdom of his plan to unite all things - even Jews and Gentiles - under Christ (Eph.3.10). It is through this that God ends hostility and brings peace to his creation.
Churches modeled on the homogenous unit principle reinforce to the world the exclusions and segmentations the world has created. We are in danger of denying the power of God to bring peace to the world.