This was the devotion at yesterday’s staff meeting:
Pray Without Doubting
If you believe, you will receive whatever you ask for in prayer. Matthew 21:22
Before you pray, check to see whether you believe or doubt that you will be heard. If you are doubting or uncertain, or if you are merely trying prayer to see what happens, your prayer won’t be worth anything. For you aren’t keeping your heart steady but letting it wobble back and forth. As a result, God cannot give something to a person who doesn’t hold her hand still.
Imagine how you would feel if a person had earnestly asked you for something but then said to you, “I don’t really believe you will give it to me,” even though you had promised that you would beforehand. You would thing he was mocking you by his request. You would take back everything you had promised and perhaps even punish him on top of it.
How can it please God when we do the same to him when we pray? God assures us that when we ask him for something, he will give it to us. By doubting him, we call him a liar and contradict our own prayers. By not believing him, we insult God’s truthfulness, the same truthfulness we rely on when we pray. This is why we say the little word Amen at the end of our prayers. We use it to express our firm, heartfelt faith. It’s like saying, “O God, I have no doubt that you will give me what I ask for in prayer.” 
This one was an interesting one, because it sounds like Luther is promoting prosperity gospel. Ask for it, pray hard enough for it, believe you will get it, and poof, you get it. It doesn’t sound like Luther. My thought is this was very early in Luther’s career. But other than that, I’m left scratching my head.
Most of the time I like this devotional book. Other days, like yesterday, I wish the editor gave us some context: when this was written, to whom it was written, etc. Context plays an important role, especially when reading Luther.
If anyone could shed some light on this, I’d appreciate it.
 James C. Gavin, editor, Faith Alone: A Daily Devotional, (Grand Rapids: Zondervan, 2005), devotional for January 26.