Another reason not to align the Christian faith with one party is that most political positions are not matters of biblical command but of practical wisdom. This does not mean that the church can never speak on social, economic and political realities, because the Bible often does. Racism is a sin, violating the second of the two great commandments of Jesus, to “love your neighbor.” The biblical commands to lift up the poor and to defend the rights of the oppressed are moral imperatives for believers. For individual Christians to speak out against egregious violations of these moral requirements is not optional.

However, there are many possible ways to help the poor. Should we shrink government and let private capital markets allocate resources, or should we expand the government and give the state more of the power to redistribute wealth? Or is the right path one of the many possibilities in between? The Bible does not give exact answers to these questions for every time, place and culture.

I know of a man from Mississippi who was a conservative Republican and a traditional Presbyterian. He visited the Scottish Highlands and found the churches there as strict and as orthodox as he had hoped. No one so much as turned on a television on a Sunday. Everyone memorized catechisms and Scripture. But one day he discovered that the Scottish Christian friends he admired were (in his view) socialists. Their understanding of government economic policy and the state’s responsibilities was by his lights very left-wing, yet also grounded in their Christian convictions. He returned to the United States not more politically liberal but, in his words, “humbled and chastened.” He realized that thoughtful Christians, all trying to obey God’s call, could reasonably appear at different places on the political spectrum, with loyalties to different political strategies.

Another reason Christians these days cannot allow the church to be fully identified with any particular party is the problem of what the British ethicist James Mumford calls “package-deal ethics.” Increasingly, political parties insist that you cannot work on one issue with them if you don’t embrace all of their approved positions.

This emphasis on package deals puts pressure on Christians in politics. For example, following both the Bible and the early church, Christians should be committed to racial justice and the poor, but also to the understanding that sex is only for marriage and for nurturing family. One of those views seems liberal and the other looks oppressively conservative. The historical Christian positions on social issues do not fit into contemporary political alignments.