You must believe that prayer can and will do anything. Have faith in your own faith!!!
We doubt because we can't see it, we can't feel it, we can't smell or taste it; but yet we believe in gravity and all kinds of other things that we can't necessarily comprehend. Of all things to believe in and have faith in, I would say that Jesus should rank right at the top. God has given us the gift of grace so that we might have faith; faith in Him, His Son, and the Holy Spirit. All you have to do is read through the New Testament and you will see the unbelievable love that Jesus has for His children. Believe in that, have faith that Jesus hears your prayers, and rely on His steadfast love and compassion He has for us. Prayer is communicating with God. Your sincere, heartfelt prayers will not go unanswered. You have developed and grown your faith through your study of the Bible; now have faith in your own faith and in God's love.