Lyricist David Byrne wrote "Once in a Lifetime" like a religious sermon. He uses the cadence, timbre, and rhetorical techniques of preachers as his character sings about the realization of the great place the world is.
Byrne says, "So much of it was taken from the style of radio evangelists. So I would improvise lines as if I was giving a sermon in that meter, in a kind of hyperventilating style." That "hyperventilating style" that Byrne adopts reflects the passion and intensity of preachers.
Intensity is built up throughout the verses with repetition. Each line begins the same, employing the rhetorical strategy of anaphora:
And you may ask yourself: how do I work this?
And you may ask yourself: where is that large automobile?
And you may tell yourself: this is not my beautiful house!
And you may tell yourself: this is not my beautiful wife!
This pattern continues throughout the entire song, which is fitting considering that beneath the track is a looping the bass riff.
Another aspect of the preacher style shapes the chorus: call-and-response. Call-and-response is a musical technique where one melody line seems to respond to the previous one. Gospel music and gospel preachers use this heavily. A gospel sermon is more than a preacher talking to the crowd; the preacher will rile the crowd up to get them involved, feeding off their murmurs and comments, and then everybody breaks into song and dance.
Listen to the chorus and see how the melody of "Letting the days go by" and "let the water hold me down" seem to argue with each other. It builds a kind of reverent excitement and celebratory mood in the song.