Many of you have probably already seen this video of John Piper responding to President Obama on abortion. I saw it on several blogs.
My point here is to point out that this is a powerful example of how preachers can engage the public square. It is clear in this video that Piper is not arguing for a certain political party. He is engaging a moral issue and makes that very clear. He boldly confronts sin, calling it by name. He adresses the president directly. At the same time, he stresses his willingness to support the president, his prayers for him, and even where he has rejoiced in him.
I felt echoes of Chrysostom, Knox and the Covenanters as I listened.