The Urth of the New Sun begins as a space opera – a turbulent journey along the corridors of space and time…

There the stars swarmed still, but it seemed to me they formed a great disk in the sky, and when I looked at the edges of that disk, I saw they were streaked and old. Since that time I have often pondered on that sight, here beside the all-devouring sea. It is said that so great a thing is the universe that no one can see it as it is, but only as it was…

Then the monstrous spaceship arrives at the planet Yesod and there Gene Wolfe takes a stab at cabbala following the formula ‘as above so below’. In the Tree of Life Yesod is the sephirah right above and nearest to Malkuth: the kingdom or our material world. And there Severian is being judged by Zadkiel – the archangel of freedom, benevolence and mercy – and at last found worthy.

What you call time is made up of such waves, and as the waves you saw existed in the water, so time exists in matter. The waves march toward the beach, but if you were to cast a pebble into the water, new waves, a hundredth or a thousandth the strength of the old, would run out to sea, and the waves there would feel them.

On returning to Urth Severian discovers that he arrived somewhat in the past so there is a smart time loop and he starts working miracles not unlike those described in the New Testament and the story becomes unintentional or, maybe, intentional fun.
And eventually the book ends up as a flowery mockery of mythologisation of earthly events and history.
Everything in the universe runs in circles.