Theology is an enigmatic double-disc collection of original recordings and covers. The songs on both discs are nearly identical, the difference is that on the versions Sinéad O'Connor recorded in Dublin she is accompanied solely by her own and Steve Cooney's acoustic guitars, and on the latter set, recorded in London, she was backed by a rotating band full of studio musicians who include everyone from bassist Robbie Shakespeare and drummer Matthew Phillips, to pianist Toby Baker, guitarist Mark Gilmour, and strings. The sheer minimal approach of the Dublin set carries within it a kind of authority, in her own elegant yet poignant tunes such as "Something Beautiful," "Out of the Depths," the tender "Dark I Am Yet Lovely," the minimal waltz that is "If You Had a Vineyard," and the nearly whispered "Whomsoever Dwells," (a kind of title track for her rarities, B-sides and live collection of the same name in 2003 called She Who Dwells...), and a truly moving reading of "By the Rivers of Babylon." The London Sessions are no less eerie, but they are, in essence, different songs when filled out by a larger group of players. Here, "Something Beautiful," with its strings and slippery drum kit, is nearly a processional. The reading of Curtis Mayfield's "We People Who Are Darker Than Blue" has a 21st century soul vibe without losing the author's soulful spirit of brokenhearted frustration moved to anger. It's a unity hymn, and O'Connor's voice underplays the words as the music, in semi-hushed tones -- the strings and a wah-wahed electric guitar -- drive the track, but it's the synth bassline that grabs the attention. There is a greater drama and a subdued ferocity in its groove. O'Connor also covers "I Don't Know How to Love Him" from the musical Jesus Christ Superstar, with a slinky reggae backbeat, dramatic strings and drum loop, it's theatrical, but she's got the voice for the tune and there isn't a hint of irony in her delivery; it would have been so naked on the acoustic record, so she wisely left it off. For "Glory of Jah," a harp and organ paint her vocal introduction before the cut moves into a reggae bubbler with keyboards, strings, metronomic backbeats and big fat power chords, which push it into the red. Ultimately, this will appeal to O'Connor's fans, more than anyone coming to her work for the first time. Theology is aptly named in that it sets out, however loosely, to offer the views and passions of a spiritual pilgrim effectively and passionately.