Your compassion for this man and your desire to see him both healed and saved is right before the Lord, and it is good that you have brought him to the Father in the name of Jesus.
We will join you in praying to the Father for him. Scripture teaches that we have direct access to the Father through Jesus, and we pray in the name of Jesus because the Father himself loves those who love His Son and believe that He came from God. So we come to the Father and ask for mercy for this father who is so ill.
The Bible shows us that Jesus healed many who were sick and that His healing was a revelation of the Father's heart, for the works Jesus did were the works of the Father dwelling in Him. Isaiah foretold that He would bear our infirmities, and the Gospels show Him healing the leper, the servant, Peter's mother in law and multitudes who were brought to Him in the evening. The early church continued to pray for the sick, and many miracles were wrought as they did, and we are taught that if anyone is sick he should call for the elders of the church to pray.
At the same time we must remember that healing is a sovereign work of God in His hands. Scripture gives the example of Epaphroditus who was sick and near death, and God had mercy on him, and also on those who loved him so they would not have sorrow upon sorrow. Not everyone is healed, and we do not know why in every case, for God's ways are beyond our finding out. It is wrong to put guilt on the sick person or on his family, and it is wrong to teach that God always wills to heal everyone in this life. Beware of those who offer simple formulas for healing. We can pray with confidence and compassion, and we leave the outcome in God's wise and merciful hands.
What is most urgent is the salvation of his soul. The name Jesus means the Lord is salvation, for He came to save His people from their sins. Scripture says if we confess with our mouth that Jesus is Lord and believe in our heart that God raised Him from the dead, we will be saved. To confess Him now and to submit to Him now as Lord is unto salvation and eternal life. There will be a day when every knee will bow and every tongue confess that Jesus is Lord to the glory of God the Father, but that confession then will not be unto salvation. Now is the time.
Jesus is the only way to the Father. He said that to see Him is to see the Father, and that the words He spoke and the works He did were from the Father. The Father initiated the plan of salvation by sending His Son, and the Son submitted to the Father's will even unto the cross, learning obedience through suffering, so that He might become the author of eternal salvation for all who trust Him.
So let us pray earnestly that God would have mercy and grant healing if it be His will, and above all that this man would hear the gospel and put his trust in Jesus while there is time. If you have opportunity, share with him simply who Jesus is and what He has done, and encourage his family to call for godly elders to pray for him and to speak to him about the Lord.
Father, in the name of Jesus we bring this father before You. You see his sickness and his need. Have mercy upon him and grant healing according to Your will and Your power. Above all, open his heart to know Jesus as Lord and Savior, to confess Him and believe that You raised Him from the dead, that he may receive forgiveness and eternal life. Comfort his family and give them peace as they trust him into Your hands. Amen.