"Man cannot avoid suffering; and in this respect his strength must stand the test, that is to say, he must endure without complaining and feel his worthlessness and then again achieve his perfection, that perfection which the Almighty will then bestow on him."
--Beethoven, 1816

I am one of the rare persons whose favorite Beethoven is 'late' Beethoven (which begins roughly at the time he wrote the letter quoted above). His late quartets and sonatas in particular exude a mystical detachment that I have not yet heard from any other classical composer. This is a shame: as Berlioz, Brahms and Wagner went on to fight over B's legacy, they chose to focus mainly on his 'middle' or 'heroic' period (and the symphonies in particular) as the standard from which European music should 'progress'. Late Beethoven, so inscribed with B's own suffering and purification, is the option never taken. For my part, I have often used the late pieces as studies in preparation for liturgical composition because they tend to break my mind out of the closed harmonic world that tended to reign in Europe from Bach to Stravinsky, and in which I was trained.

Finally, it is interesting to note that during this late period, B himself turned to Palestrina and Josquin and even chant occasionally for his own inspiration. Some moments of the great Quartet in C# minor almost sound like transcriptions of Renaissance polyphony.

Peace to you in Jesus Christ, whose suffering has merited for us divinization!