...and no, you can't "Vote for Jesus" to be President.

Last week I wrote a post on “The top ten most difficult doctrinal/theological subjects that contemporary Christians need to address.” Today I want to invite readers to leave a comment recommending books on these topics that you have found to be helpful. The fifth item on my list was political allegiance and ecclesiastical unity about which I wrote:

I don’t know how this goes elsewhere, but our election season can be a nasty time for Christian unity. Often pastors preach overt sermons supporting particular political ideologies or sometimes their views leak into their sermons. People may begin campaigning for a particular party in such a way that it causes friction with Christians who support other parties or candidates. Even more discouraging is the way politicians adopt the rhetoric of Christianity in order to win votes.

What is a book (or books) that you recommend for someone wanting to think through this subject?