I've already linked to TypeBlogs.com, but I like this stuff so much and find it valuable enough that I might as well continue to promote it by pointing out Marla's post on her own blog about the venture.
At ...in the outer..., we have an argument for why Christians have a moral obligation to seek out and befriend those of other racial and ethnic groups. It sneaks in the back door out of a consideration for why Christians ought to seek out fellow believers beyond our natural tendency to form friendships with those people we've got something in common with. The Christian call is to be part of friendships with other believers both to build into them and to be encouraged and sharpened ourselves, and in a multicultural society that's going to require active initiation with those across ethnic and racial lines. We're certainly not going to be drawn to worship with those whose preferences for worship are very different from our own. I think this is right. If we're actively engaged in the lives of those who are very different from us, we will be worshiping with them in the more general New Testament sense of what worship is, and that will lead over time to a tendency to work into our sense of public worship as iron sharpens iron to make each different ethnically-associated public worship (or otherwise divisive exclusivity of style) into something that seeks biblical principles to guide it and allows our differences to shape the rest. This may be a long-term that process, but it's likely to have more long-term effect than anything else I can think of.
all kinds of time... compares our situation with the early church in terms of the two sorts of culture, the one Christians found themselves coming out of and the one that shared far fewer assumptions, about the nature of reality and the nature of morality. Our cultural centers are far removed from the basic assumptions most Christians have, which small town life more easily fosters. I do hesitate at thinking of the Judaism Christianity came out of as the friendly culture, given how strongly Paul critiques his contemporaries' reactions to Christ, describing their resistance to the gospel as just as strong as the resistance of the Gentiles. It's true, though, that they shared more assumptions with the Jews who accepted their Messiah than the Gentiles tended to share, and both elements (the resistance to the gospel and the shared assumptions) are true of small-town America, as opposed to the cultural centers. David argues that we need people like Paul to go into the cities and do what Paul did, speaking the gospel in the language people of the cultural centers will understand. Amen.
Pseudo-Polymath raises some good pros and cons regarding world unification.