Nietzsche is very playful. I think he must have laughed as he wrote the very playful sections of that book.
Take for instance the part where Zarathustra says laughter killed the gods when one of them said there’s no gods but god.
In part four in conversation with the retired pope, Zarathustra says pity for man killed god, that is, god could not stand the man on the cross and died out of pity. In the same place he says
He was a concealed god, addicted to secrecy. Verily, even a son he got himself in a sneaky way. At the door of his faith stands adultery.
Elsewhere he writes about god this
When he was young, this god out of the Orient, he was harsh and vengeful and he built himself a hell to amuse his favorites. Eventually, however, he became old and soft and mellow and pitying, more like a grandfather, but most like a shaky grandmother. Then he sat in his nook by the hearth, wilted, grieving over his weak legs, weary of the world, and one day he choked on his all too great pity.
And finally on love( especially the way Christians and religious people don’t tire to tell us god is love, Zarathustra says
Whoever praises him as a god of love does not have a high enough opinion of love itself. Did this god not want to be a judge too? But the lover loves beyond reward and retribution.
Have yourselves a humorous day, won’t you!