Numbers 15:15-16 states:
The community is to have the same rules for you and for the foreigner residing among you; this is a lasting ordinance for the generations to come. You and the foreigner shall be the same before the Lord: The same laws and regulations will apply both to you and to the foreigner residing among you.
In context this is talking about regulations for a food offering at the temple. What does this have to do with our current situation? In respect to ecclesiology it would appear that God wants us to treat foreigners as part of our community, especially if they have made the conscious personal decision to participate in the worship of the church. While ethnic churches are a reality in many cities, we must work towards intergenerational and multi-ethnic participation that will bring us to appreciate the diversity of the body of Christ in a more rich way to reflect the unity the Apostle Paul discussed in Ephesians 2 (which you should look up and do some Bible study on).