U2 were in a really rough place when they recorded October, their second album. Bono lost a suitcase containing all of his lyrics (it was recovered just a few years ago) and he, the Edge and Larry Mullen, Jr. were deeply immersed in a Christian organization called the Shalom Fellowship that made them question their decision to be in a rock band. Spiritual matters are at the core of several songs on the record, though "Tomorrow" is about the death of Bono's mother.
The disc wasn't a big seller, though "Gloria" did get some radio and MTV play. They rarely do any of this material in concert, though "Scarlet" was played a bit on the 360 Tour.