Little devotional books are popular in the LCMS. These kinds of books tell a 200-word story with a basic message, one for every day. There are periodicals our publishing house publishes, devotional books, and even some web-based devotional stories.
I always appreciate it when I learn that members read these on a daily basis. I'm glad that they take a few minutes for this devotional time. When I was in college I used one of these...but I also cheated. You see, they usually proscribe a reading of a pericope or chapter, along with the single verse printed at the top of the page. I usually "overlooked" the longer passage, read the single verse, the flash-devotion, said the one-sentence prayer at the end and called it quits. Devotions done! Now on to life.
This obviously is not the intent of those who produce devotional books like this. At minimum, the entire passage is supposed to be read, and the prayers are usually intended as a start for prayer. I know this; I've written some of these before (but not for a Lutheran publisher...shh!). But I fear that many people consider that "doing devotions" means reading a little story, saying a prayer and getting on with life. One website puts it this way: "What most people talk about when they talk about devotionals is a book that helps you grow in your relationship with God." (source)
That's not exactly how it is supposed to work. Devotion(s) are defined as "An act of religious observance or prayer, especially when private. Often used in the plural." (American Heritage Dictionary ) Prayer. That's the action of daily devotions. What Christians do privately, outside of the liturgy is, well, some of what they do inside the liturgy: pray and mediate on Scripture.
For this reason, we Lutherans have hymnals that are designed not just for church use, but also for home use, with short orders of worship, daily reading tables and much of the psalter (book of Psalms). There are other options, like the Brotherhood Prayer Book (an independent Lutheran diurnal I have no experience with) or The Monastic Diurnal (not just for monks...but hard to use, Catholic--or Orthodox if you will, and a treasure for the patient or stubborn!). Apparently Concordia Publishing House refused to be left out of the fray and have designed their own diurnal, the Treasury of Daily Prayer (I don't know that much about it this one, but ought to check it out). But whatever source you use, the object is not reading stories to warm our hearts, but praying to God, praying with the psalms, and praying with the Church, i.e., praying along with the Church Calendar in the season, the commemorations, and so forth.
To be clear, there's nothing wrong with reading inspiring little stories that you may find in all kinds of sources. On the contrary, these are good! But we shouldn't limit ourselves to them. Christians need to pray the psalms, to mediate on Scripture, and be encouraged in Christian living through short (or long) homilies, exhortations, lives of saints, meditations from Church Fathers, contemporary stories and devotional reading too. All this will feed and nurture faith in ways it is impossible to reckon.