What this song is about is when at one time in the not too distant past, one political party in Ireland considered themselves Catholics and another political party in Ireland considered themselves Protestants, they could not compromise over political issues so they started killing each other instead. Christians killing other Christians in a civil war. If divisive discourse leads to political parties hating one another, this type of thing could repeat itself. GOD is bigger than politics and all the politicians in the history of the world put together.