Most books on church planting, church growth and ethnic ministries use the Homogeneous Unit Principle (HUP). Don’t be scared off, this is just a big term for what we all know and observe; that people want to be with people who are like them. We see it every day in who we gather around us as friends, who we spend time with at parties and where we choose to live.
The argument goes that if we want to succeed in ethnic ministry, we should gather people of like ethnic backgrounds, and that will attract others of the same ethnic background to the group and permit the gospel to be heard.  It is said this has more drawing power than an ethnically diverse group.
Its great strength is that it does describe the way people operate. People prefer gathering with people like them. If we think about our churches, people make their choices on whether to join using this principle; whether it be on the basis of age, wealth, proximity, or enjoyment of particular styles. Since the 1980s our churches have fostered this by promoting the perception that newcomers must feel like they belong before they can be asked to believe, and so cultural similarity has been the order of the day.
However, this way of thinking as the organising principle is sub Christian! It feeds off and can legitimise people living in self centredness.  At the heart of Christian living is self sacrificial living for Jesus and for others, whereas a church created for comfort and sameness can create an lifestyle of ease, not service for the believer. It can make people forget that we are all one in Christ Jesus.
So do we discard the idea of establishing ministries where like attracts like? No – it is a powerful tool in thinking about how we can structure our lives together to reduce the unnecessary obstacles to the gospel. We should work for the gospel to be the only barrier for people. We should not expect those outside faith to have to fit into our existing and often foreign cultures to hear the truth. Like Jesus, we need to be prepared to forsake our ease for the salvation of others.
But we must never let the reason for our meeting be our homogeneity. We meet together because God draws us together from every language, tribe and race to encourage each other as the day draws nearer.
The test of whether it is our sameness or the gospel that shapes our churches shows up in the attitudes of the members. Are those who joined a homogeneous group, in time keen to meet with believers of any ethnic group?  Do they understand that they meet together not to feel comfortable with their own, but as an evangelistic opportunity to reach others? If not, the bar of Christian commitment has been lowered from service to ease!
In 1981 we commenced a ministry to second generation Greeks. But fairly quickly the unit became minority second generation migrants, as Greeks, Italian, Lebanese, and Spanish joined us. This was because ‘wogs’ are friends with ‘wogs’, a grouping bigger than national boundaries. The lesson? Be prepared to reassess the unit you are reaching.
Secondly, with a group from a common background, it is often easier to target significant issues of faith and error that are particular to that group, which is marginal to broad stream church life. For example, in our ministry the issue of family shame at being protestant rather than Greek Orthodox had to be dealt with.
What I am suggesting is that our ethnic distinctions are a gift which may be used by God to draw others into his Kingdom, and so it is not inappropriate to gather people of like backgrounds.  But when what holds that gathering together is homogeneity rather than the gospel, the gospel is lost, as it is the Lord who died for each of us, who draws believers together.  We must ensure that we proclaim unity through Christ rather than unity through culture.