In this video, John Piper preaches about the combination of instruction with emotions in the Psalms. Watching this video is a half-hour well spent.
The Psalms are poems. They are songs. They were sung, and they are poetry. The point is this, poetry and songs – music – exist to stir up and express emotion. That’s why it exists. If that weren’t the point there’d only be prose. The only reason anybody does anything kind of weird with language, called ‘poetry’, is because they want something else to happen! They want something to happen when they say this. The only reason we sing, and don’t just stand here talking to each other is because we want something else to happen. We don’t just want to inform each other of ideas, right? It’s not the point of getting together, just informing each other of more accurate ideas. We sing and we write poetry – we do that sort of thing because we know we have another HUGE aspect to our being called a heart, or an emotion, or affections, and we are to be deeply affected there, and shaped there by Psalms.