Matthew 21:22 And whatever things you ask in prayer, believing, you will receive.
Just as it is impossible for some to believe that Christ rose from the dead, many will not believe that our prayers will be answered if we fully trust in Christ.
We must trust in the whole Gospel and not just the parts that we think are easy to believe. We must trust God, Christ and the Holy Spirit because they will always act together as one; that is the essence of our faith, that God is always true.
Christ has achieved the impossible so that we can beat the impossible and live the impossible with Him. So why doubt that He can answer the impossible?