It makes perfect sense. The thing is, a sermon or a book is supposed to be focussed. Teachers and writers are taught to focus on one thing--to create a thesis statement or a learning outcome--and then organize all their information around that one thing.
So we have heaps of sermons and books that are wholly dedicated to one topic or one passage of scripture. And it's an effective way of teaching, because it facilitates learning. In order to process information, we need to organize it. Compartmentalizing helps us to retain information. Our minds are vast, but they are limited to how much they can digest at once and how much they can retain.
God, I believe, is far bigger than our intellectual capacity. He is bigger than mine, I know that for sure. So it helps to study one aspect of God at a time. But I think it also hinders, because we often keep those aspects separate. A handful of aspects resonate with us and we hold on to them ponder them (often one at a time) over and over again until we have what seems to be a fairly manageable concept of the divine. And we (if we are at all like me) forget to bring those aspects together all at once and to remind ourselves of all the other aspects of God that we don't think of often (He is jealous, He is just, He is Merciful all at once). And the God that we register in our minds--one aspect at a time--is kind of underwhelming.
It is crucial, I believe, to remember that God is bigger than our human minds--that he is beyond comprehension. In the book of Job, Job's friends gather, using their knowledge of God to admonish Job. Job answers them, defending himself, and revealing his own knowledge of God. This goes on for just over 35 chapters. They're intelligent men, all of them, and they have a lot of intelligent and reasonable things to say about God and life in general. Then God speaks up. Where were you when I laid the foundation of the earth? He asks, in 38:4. He proceeds to ask a long series of humbling questions, revealing the both the limitations of human comprehension and the vastness of His own. Read it for yourself; it's really stunning.
God has given us teachers, but they are no substitute for communicating with him. Whatever we learn though our teachers and writers, it is imperative that we continually remind ourselves that there is more. I'm convinced that it is only through God that we can truly be overwhelmed by God--that we can catch a glimpse of his vastness. As soon as we try to communicate that vastness with one another, it is diminished by our limitations. I'm not saying we should stop learning together and from one another. There is incredible value in fellowship and in sharing our knowledge. But only God can overcome the limitations of language and learning to reveal something of His incomprehensible self.
So I would encourage you to remind yourself daily--if you don't already--that God knows more about God than anyone else. That all the learning in the world cannot substitute for hearing from God himself. Make time to seek Him and meditate on Him. Before you engage with the Word, ask him to be your teacher and to open your mind to the things you cannot comprehend on your own. And I'll try to do the same!