Which of you, if his son asks for bread, will give him a stone? Or if he asks for a fish, will give him a snake? So if you who are evil know how to give good gifts to your children, how much more will your Father in heaven give good things to those who ask Him!
Some prayers get said so often that the words wear smooth, like a pebble kept in a pocket. They tend to ask for something particular, such as a certain job, a certain person or a flat with a bit of garden. When the answer keeps not coming, a worried thought can settle in beside the prayer: God promised me this, so either he has let me down or I asked the wrong way.