Therefore I say to you, whatever things you ask when you pray, believe that you receive them, and you will have them.
(Mark 11: 24)
Many times we stop at verse 24 in Mark 11, but let's go onto verse 25 and 26.

Have you ever noticed that every time Jesus taught on prayer He mentioned forgiveness? If my prayers were not being answered, the first question I would ask myself would be, "Am I holding something against someone?" or "Have I forgiven those who have done me wrong?"

Jesus said:
And whenever you stand praying, if you have anything against anyone, forgive him, that your Father in heaven may also forgive you your trespasses.

But if you do not forgive, neither will your Father in heaven forgive your trespasses.
(Mark 11: 25-26)
I was meditating on this verse one day and decided that this may be the reason so many people kneel to pray.

Jesus said, "When ye stand praying, forgive." Maybe they think if they kneel, they don't have to forgive!

If I were having trouble with my prayer life, I would check to be sure I was walking in forgiveness.

Unforgiveness will stop your faith from working. Unforgiveness is a thief of life and a thief of faith.

Source: Releasing God's Power Through Prayer by Charles Capps.
Excerpt permission granted by Harrison House Publishers