Understanding Christianity today
Although perhaps this seems completely unrealistic in today's day and age, this book brings up some important points from real Christian history. It wasn't that long ago that Christians used the Bible to enforce their misguided, hateful opinions on issues like slavery and women's rights. So this novel's dominant thematic message is that the church needs to continually revisit their opinions about scripture to figure out what Jesus would actually do, instead of just tagging scripture onto whatever they want to do in the first place.
Community
Another serious consideration of the novel seems to be the interplay of different members of community. By showing how important they all are to the common good of the community, a point is made against ostracizing people who are different, because the religion benefits from having different points of view juxtaposed in the same community, like Jack Manning, who might make some uncomfortable, but also has unique personal insight to offer.
Xenophobia and fear
The novel reminds its characters (and also the reader) that it is easy to allow fear a role of authority in one's mind. When new people come to the community, there is xenophobia and a fear about changing the status quo, which is comfortable. The point is that fear is a powerful force that can shape personal opinions, but the theology of Christianity unequivocally rejects fear that power, so to be like Christ is to love everyone, to accept change as it comes and to deal with fear by growing as a person.
