The following question was raised by someone on a Christian BB forum.  My own answer follows...

The Bible says, without qualification:

• If you believe, you will receive whatever you ask for in prayer. [Matthew 21:22]
• If you ask anything in my name, I will do it. [John 14:14]
• Nothing will be impossible to you. [Matthew 17:20]
• All things are possible to him who believes. [Mark 9:23]
• For with God nothing will be impossible. [Luke 1:37]

And yet: