"For my own part 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." —C.S. Lewis
One of the FB comments was, “What doctrinal books did Lewis read?” I think you get out of doctrinal books whatever you put into them. If I am reading them to get through them, or to debate with them, or to use them to debate with others, then they may not be so helpful. But if I read them asking, “What does this tell me about God? About myself? About our world? Is this true to scripture and my experience?” then I think that doctrinal books can be extremely devotional. It depends, however, on the attitude that we bring to the books.