This term I'm taking a (graduate) course which is crucial for my degree. The teacher's plan for the course is quite ambitious and all along he's been following the structure of a given text, but he doesn't follow it completely and quite often omits (what I consider) key results from it, e.g. results which motivate or deepen the understanding of definitions or other results. To put it bluntly, he leaves a lot of gaps that the book covers nicely.
It's been a frustrating process and we're soon going to start with a very important topic and I've been wondering how to approach him about this. My idea at the moment is to ask him to follow the textbook more closely, even if by doing so we sacrifice how much we cover, but I'm looking for suggestions.
Final edit (concluding remarks): I've chosen the answer which I think gave me the best course of action and I think summarizes some of the most important points in comments and other answers. Anyone reading this thread in the future should definitely check all of them anyway. They all provided valuable feedback for me.
I'd also like to point out that Shane's comments in chat are spot on. I believe said comments capture the exterior root of my problems, which I was unable to see at the time when the question was written. On my end I also learned a couple of important things on how to deal with these kind of situations.