John Eliot Gardiner, Bach: Music in the Castle of Heaven
(New York: Alfred A. Knopf, 2013), p. 476, with endnote on p. 596:
Towards the end of his more than thirty years as music director of Berlin's Singakademie in 1827, Carl Friedrich Zelter wrote to his friend Goethe, 'Could I let you hear some happy day one of Sebastian Bach's motets, you would feel yourself at the centre of the world. I hear the works for the many hundredth time, and am not finished with them yet, and never will be.'34 After knowing them for more than sixty years I feel exactly the same. The glorious freedom that Bach exhibits in his motets, his balletic joy in the praise of his maker and his total certitude in the contemplation of death—this, surely, is the best possible response to our mortal entrapment.
34 Briefwechsel zwischen Goethe und Zelter, Vol. 2: 1819-1827, Ludwig Geiger (ed.), p. 517, quoted in Schweitzer, J.S. Bach, Vol. I, p. 241.
Id., p. 478, with endnote on p. 597 (a minor misprint corrected):
Bach in fact makes it a great deal easier for us to focus on the injunction to love one's neighbour than on all the filth and horror of the world. We emerge from performing or listening to a Bach motet chastened, maybe, but more often elated, such is the cleansing power of the music. There is not a whiff here of those 'foul fumes of religious fervour' that Richard Eyre sees today 'spreading sanctimoniousness and intolerance throughout the globe, while those far-from-exclusively Christian virtues—love, mercy, pity, peace—are choked.'37
37 Richard Eyre, Utopia and Other Places (1993).
I like those YouTube videos that show the musical score, thus allowing one to sing along, e.g. O Jesu Christ, mein's Lebens Licht