"I tend to find the doctrinal books often more helpful in devotion than the devotional books, and I rather suspect that the same experience may await many others. I believe that many who find that 'nothing happens' when they sit down, or kneel down, to a book of devotion, would find that the heart sings unbidden while they are working their way through a tough bit of theology with a pipe in their teeth and a pencil in their hand."
This gets to the root of what I am attempting to say, but from a different perspective. Lewis is basically saying that deeper issues like theology and doctrine, rather than shallow inspirational fluff, cause you to think, study and know truth about God. In other words, if you read about God's omniscience it will land deeper in your life and heart due to the very depth of the topic demanding your attention and thought. This will help stir embers of love and zeal instead of the flash burn from an inspiration-a-day calendar that says "God knows more than you, so trust Him". Feel free to share your thoughts, ideas, or practices with reference to your devotional time.