I think of it like learning mathematics.
Initiates have to learn a dead language - like learning the syntax and semantics of logic and equations. They also learn the principles of channeling power through their souls.
Akka's training scenes with Kellhus lay this out pretty clearly. Practical experience doesn't count for much of the learning process.
You can lay down all of the knowledge and practice solving equations, but until you actually apply the theory to an event, personally channel the power from the outside and manifest physical ontalogical change, you are unmarked.
Inrau understands the theory and mechanics of Gnostic metaphysics, he just hasn't employed the power until his final scene.
Lol, this is going to be the most spoiler tagged place on tsa!
It's pretty clearly stated that
all replies must be spoiler tagged in this subforum.