"almost everything we call 'higher culture' rests on the spiritualization of, and giving depth to, cruelty"
"The spiritualization of sensuality is called love: it is
a great triumph over Christianity"
Spiritualization of the body, is imo, what Apollo does to Dionysus. It's just that religions and other spiritual blessings want to disintegrate passion and body. They want to escape. However, spirit of Zarathustra uses intellect as a means to give style to cruelty of the body (Dionysus).
Now, love and cruelty are interesting, because intellect is a means of Will to Power. Self-overcoming needs to be cruel towards something, yet love something else. Reminds me of Tyler Durden saying 'Self help is masturbation, but self destruction...' (I rarely quote Fight Club, not one of those) Cruelty, in this sense, is 'applying the knife' to your desire, and yes, Nietzsche called this sickness!
It is a disease, the bad conscience—that is not subject to doubt
—but a disease as pregnancy is a disease [GM II 19].
"spirit is the life that itself cuts into life" (Z II 8)
Apollo gives style do Dionysus. I like to say that Dionysus sees himself with Apollo's eyes. Spirit is for Nietzsche, self-overcoming. It's making the sculpture, cutting your garden only to give space for something better to grow.
In Twilight of Idols he calls lack of will, lack of 'spirituality'.
The world of reason is to be regarded as a great and immortal being, who ceaselessly works out what is necessary, and so makes himself lord also over what is accidental. - Goethe