“Therefore I say to you, whatever things you ask when you pray, believe that you receive them, and you will have them” (Mk 11:24). Is this really true? It is helpful to note that the word given here as “ask” is better translated “desire,” and strong desire at that. The same word is also rendered “requiring,” “begged,” or “craved.” And this is the key to the promise.
Andrew Murray explains: “Desire is the soul of prayer, and the cause of insufficient or unsuccessful prayer is very much to be found in the lack or feebleness of desire.… A Christian may often have very earnest desires for spiritual blessings. But alongside of these there are other desires in his daily life occupying a large place in his interests and affections. The spiritual desires are not all-absorbing. He wonders that his prayer is not heard. It is simply that God wants the whole heart.”
It may be that “the Lord your God is testing you to know whether you love the Lord your God with all your heart and with all your soul” (Dt 13:3).