Mark 11 contains two verses that I am willing to guess are often misunderstood at best, and completely misused in the worst case. "Listen to me! You can pray for anything, and if you believe, you will have it. But when you are praying, first forgive anyone you are holding a grudge against, so that your Father in heaven will forgive your sins too," Mark 11:24-25.
If I pray for it, I get it. Now that has not really been my experience in life. So if I look at the passage in Mark, I pray but I do not get, therefore I must not believe. That is where the problem begins, I am pretty sure I believe. Now it is not with perfection, nor is it with consistency, but I am working at making more and more of my life a living act of believing God to be God, Jesus to be Jesus, and the Holy Spirit to be the Holy Spirit. Still, I pray, believe and do not get.
Could the answer be in the verse 25? This verse shows that it might not be a matter of belief, rather it is a matter of the heart. Not a popular notion, but it is nearly impossible for God to deal with our prayers if our heart is out of sync. Having our heart in sync with God is not a matter of having it all together, nor is it a matter of being completely righteous and holy. Having our heart in sync with God is a matter of having an appropriate understanding of our standing with God. To have done the work of understanding the condition and position of our heart.
When we ask God for something in prayer there are two pieces of the puzzle that must be in place. First we must believe God to be God. Second, the condition of our hearts must be in sync with God. Often the belief part is not what is out of place.