[...] “What is the significance of Kundry's kiss?” - That, my beloved, is a terrible secret! You know, of course, the serpent of Paradise and its tempting promise: “eritis sicut Deus, scientes bonum et malum.” Adam and Eve became “knowing”. They became “conscious of sin”. The human race had to atone for that consciousness by suffering shame and misery until redeemed by Christ who took upon himself the sin of mankind. My dearest friend, how can I speak of such profound matters except in a simile, by means of a comparison? But only the clairvoyant can say what its inner meaning may be. Adam - Eve: Christ. - How would it be if we were now to add to them: - “Anfortas - Kundry: Parzival?” But with considerable caution! - The kiss which causes Anfortas to fall into sin awakens in Parzival a full awareness of that sin, not as his own sin but as that of the grievously afflicted Anfortas whose lamentations he had previously heard only dully, but the cause of which now dawns upon him in all its brightness, through his sharing the feeling of sin: with the speed of lightning he said to himself, as it were: “ah! that is the poison that causes him to sicken whose grief I did not understand till now!” - Thus he knows more than all the others, more, especially, than the assembled Knights of the Grail who continued to think that Anfortas was complaining merely of the spear-wound! Parzival now sees deeper. - Thus he, too, sees deeper who does not believe what the whole world believes, that I, for ex., have suffered as a result of the failure of my Tannhäuser in Paris, that I have suffered through the newspapers’ attempts to detract from my fame, or through lack of recognition: Oh no! my suffering goes deeper; he who would know of it must hear in my works themselves what superficial listeners cannot hear. Happily, it is an awareness not of sin but solely of redemption from the sin of the world. But who has divined this redemption in my works? -
Source: Selected Letters of Richard Wagner, trans. and ed. Stewart Spencer and Barry Millington (W. W. Norton & Company, 1988), No. 333