A lot of ideas get re-used and made part of new songs if the first version didn't cut the mustard, and the stuff that gets left off usually contained the germ of something good but failed to reach a satisfactory state by the recording stage.
Prayer is naught else but a yearning of soul. . . it draws down the great God into the little heart; it drives the hungry soul up to the plenitude of God; it brings together these two lovers, God and the soul, in a wondrous place where they speak much of love.