Thomas Watson, a Puritan pastor from over 350 years ago, asked in his book, Body of Divinity (pp. 399–400), “Why does God delay an answer to prayer?” In other words, why would God ever keep us asking and seeking and knocking when he could respond sooner? (cf. Luke 11:9-10) He gives four answers :

1. Because He loves to hear the voice of prayer. “You let the musician play a great while before you throw him down money, because you love to hear this music.”
2. That He may humble us. We may too easily assume we merit some ready answer, or that He is at our beck and call like a butler, not as sovereign Lord and loving Father.
3. Because He sees we are not yet fit or ready for the mercy we seek. It may be He has things to put in place—in us or in our church or in the world. There are a million pieces to the puzzle. Some things go first to make a place for the others.
4. Finally, that the mercy we pray for may be the more prized, and may be sweeter when it comes.