This past Sunday, I preached on Psalm 133. It is one of the great psalms of the Psalter. And it is addresses one of the important subjects of the Christian life: spiritual unity. For the record, I love the psalms. Like many Christians, the psalms sustain my devotional life through its various seasons. I find preaching the psalms to be difficult, but rewarding. It forces me to plunge deeper into these great hymns of faith. Psalm 133 addresses the subject of spiritual unity in an interesting fashion. It is not a song, but a sermon. In it, David does not...