This past Sunday was Trinity Sunday, or the feast day devoted to celebrating the Christian doctrine of the Trinity. This meant that hymn-singing churches were forced to shuffle through the ecclesiastical cabinet for anything that emphasizes and lauds the Holy Trinity. Holy, Holy, Holy, one of my all-time favorites, was probably at the top of a lot of music director's lists, but I imagine St. Patrick's Breastplate was up there as well. We sang it at my church.
The Breastplate is an odd song with an odd tune and it comes from an odd people. Chesterton talks about the Gaels of Ireland as the men that God made mad, for all their wars are merry, and all their songs are sad. Growing up among the Irish in America, I'd say that's about right. There's a fierceness, an a mystic tenacity about St. Patrick's Breastplate that's quintessentially Irish. It's a hymn for those who see the supernatural as a plain fact, as plain as potatoes. The hymn claims the doctrines of the Church and the events of the life of Christ for the singer as a performative speech act: to say the thing is to make it so. Saying the doctrines is to put on real armor. It was written for a people who believed in demons, feys, and sorcerers, and that survival meant invoking heavenly power against dark magic. It's a fighting man's hymn, for those who know that there are things that go bump in the night. None of that's particularly comfortable to say outside of Pentecostal circles or maybe when you're hanging out with M.K.s who've seen "stuff."
So where am I going with all this? The Trinity is often pointed out as a useless or confusing doctrine; something to be believed because you're required to and useful for calculating who's in and who's out. To St. Patrick it wasn't though. To him it was a revelation of the nature of God, and a powerful protection against all the works of the devil; things real and immediate, not vague and allegorical. Singing the Breastplate brings us back to a dark time when news that God, Father, Son, and Holy Ghost, himself had entered the ring in the struggle against darkness and night broke like morning after a storm, or light on drawn swords. It reminds us of a time when the servants of the Triune God saw themselves as come to drive out serpents, and believed that they had been given power to do so.