Going from reading passages of the Bible to reading a book that applies that book has been problematic. I was in a system and that system needed to change to make me see more of the relevance.
The problem with change is that it is messy. I found that I had set myself the goal of going from reading a whole chapter within a book of the Bible to reading a whole book of possibly 200 to 300 pages as a devotional task.
Because of the overwhelming nature of this, I found that I was reading less biblical and devotional material and not more. Even over a week or two, not reading the Bible negatively changes the way one sees the world.
I am therefore setting myself the goal of reading one chapter a day in devotional/applicational books after I have read a book of the Bible. this seems sustainable.