Dear Eileen
You are frustrated and downhearted because your prayer has not been answered, can you see into the future? Do you know what lies just ahead of you? No you don't and none of us do, but God does be sure of that. How can you say your prayers are not being answered? Do you know what God has predestined for your son or for you to come to that? Be assured that the result bad or good in our carnal sight will be GOOD in God's sight. When God predestines something for us it is for a purpose and the end result for us will be good. "And we know that God causes all things to work together for good to those who love God, to those who are called according to His purpose. For those whom He foreknew, He also predestined to become conformed to the image of His Son, so that He would be the firstborn among many brethren; and these whom He predestined, He also called; and these whom He called, He also justified; and these whom He justified, He also glorified." (Rom.8.28-30).
Don't give up on prayer it is the most powerful weapon in the world "And when he was come into the house, his disciples asked him privately, How is it that we could not cast it out? And he said unto them, This kind can come out by nothing, save by prayer." (Mark 9:28,29).
Here were apostles who could bring down fire from heaven, "And when his disciples James and John saw this, they said, Lord, wilt thou that we bid fire to come down from heaven, and consume them? But he turned, and rebuked them. And they went to another village..." (Luke 9:54-56). But they were unable to drive out a demon. So the power of prayer is mightier than calling down fire from heaven by faith.
Please do not underestimate God's predestined will because you do not know if your son's recovery is included in it or not. Why not pray for his complete recovery to be a part of His predestined will instead and leave it at that. Very difficult but it does show complete confidence in a loving and merciful God because that is what He demands complete trust and submission to His Sovereign Will.
So child of God, listen, there will be an end,
Just trust Him for His Word is true,
Be patient and wait, for in His own good time
He'll measure.and bring you through.
God bless you sister and your son in our joint walk in Christ.
Love in Christ Jesus.
Roy UK