Mumford and Sons are a kind of musical Pinterest. They “collect” without really linking together a variety of quaint, beautiful, and touching things. A little gospel here, a little Chesterton there, a little waistcoat here. Because of their penchant for gathering any and every sartorial, lyrical, and instrumental oddment, their coy references to the gospel and GKC become just the “pinning” of another striking and well-wrought thing. We don’t know if they’re Christians (or indeed if they have any existential commitment), or if they’re just aesthetic reactionaries of a limited type. Eclecticism precludes evangelism.
The whole problem is well represented by their name, “Mumford and Sons.” It suggests history, tradition, the passing down of something real—above all, the transmission of blood. But Marcus Mumford is not in a band with his sons; in fact, he has no sons at all.
Jonathan D. Fitzgerald zooms out:
Mumford & Sons are part of what I (and some others) call the New Sincerity. This is a larger movement that recognizes the artificiality of the separation between sacred and secular. They reject that pressure to fragment ourselves depending on our company. Today, I’m a spiritual person. Tomorrow, I’ll be rational. And so on. Mumford & Sons are not the first band to do this. And they’re nowhere near the best. But, understood in light of this larger movement, they can’t be dismissed as too Jesus-y or not Jesus-y enough.
Ann Powers adds a personal touch:
I know the feeling that radiates from a room full of Avetts or Mumford fans singing along with every overly sincere, earnest word; I've been there myself. At sixteen, I was a confused Catholic kid struggling to figure out how I could be my parents' daughter and still want to make out with boys, dye my hair funny colors and dance all night to ridiculously loud music. U2's music didn't present an alternative to the church life that had made me, in part, who I was then; it showed me how to struggle within that life, and get to the point where I could either walk on within it or walk away.
I'm not a practicing Catholic now, but when I hear Mumford & Sons or the Avett Brothers, I recognize the same internal fights, the same desire to grapple with impossibly big terms like "sincerity" and "belief," that U2's music helped me through twenty years ago. The frame is different: today's churchy music has more traditional trappings, connecting it with other trends like the crafts revival and sustainable living practices. But the deeper motivations, I think, are the same.