I remember reading Matt's notes on the evolution of this song when he first released it as a fundraiser for Katrina victims and I resonated with his discussion of the poor we saw literally struggling for life in New Orleans and the nudge of the Spirit (I think somewhere he said he was at a gas station in AZ) that these people too were the poor, in a different way.
And I love the way he takes the lyrics both ways in this song. I think my favorite lyric has to be alive in the promise/to be dead to the world. I like the unexpectedness of it, the PARADOX (my favorite thing after concrete imagery and possibly even more appropriate for anything dealing with the Christian life), and, let's admit it, "unwavering" is good word choice, it's straightforward and interesting at the same time.
I also appreciate the way this song evolves from the teaching of the beatitudes to the sending out. I read Dallas Willard's The Divine Conspiracy recently and as he outlined his reading of the sermon on the mount I couldn't help but think back to this song. Willard's discussion of this teaching contradicts the common interpretation of these sayings as some kind of injunction to be poor, meek, in mourning, etc in order to be blessed and receive good things by God. He even rejects the idea that there is some kind of cause and effect at work within the dynamics of the beatitude. Rather, he reads these as completely counter cultural to the crowd Jesus was speaking to (not an uncommon observation) and completely turning their world upside down by announcing that EVEN the very least and most shattered, most rejected have a place in the fold of the kingdom, and not just standing room but a place of honor and abundance. All of this is based on faith and discipleship, just an extra thought.