Thanks, Martin, for your post! We each have a measure of faith which will increase after we accept Jesus as our personal Savior and the Lord of our life! By faith, we believe in Him, and living by faith we do not need to see Him in His physical form but through God's Holy Spirit entering the believer we know He is real and alive! As He shows us more of Himself in what He can do in the Biblical Scriptures, our faith increases and then we can lean on Jesus and trust Him more and more! He has appeared to some people in their dreams, in the night while sleeping and in Spiritual Form of the man that He was born to save us all from sin by dying for every sinner who will believe in and accept Him, as God's only begotten Son! Even satan can appear as an angel of light but he is a liar and will fool whosoever will listen to his sly untruthful ways but by having Jesus within us we are directed and led by God's Holy Spirit or Holy Ghost to hear the voice of God whether audible or as a still small voice tugging at our hearts saying: Go this way or go not that way, for He directs our footsteps with righteous thoughts upon His straight and narrow path leading to eternal life with Him forever more!
Satan will tempt and get sinners and weak believers to walk the broad road with a wide gate leading right into Hell and then the Lake of Fire! Although, some are healed and some are not, doesn't mean that God doesn't love each of us for He does and He is no respector of person, so what He does for me He can do for you, but if we aren't living the way we need to for His blessings and healings we might not receive our healing, or if it doesn't fit into God's plan for anyone, as He knows the number of our days before our Spirit goes back to Him Who gave it and souls are at rest until the time of our Resurrection into immortal bodies and dwelling with Jesus where we shall never die anymore! Jehovah is Almighty and an Awesome God so to question Him when our healing or other answers to prayers doesn't happen is doubting that He exists and He does and will forever and ever!
We can pray and believe for others and, sometimes, we don't have the faith to believe that we can be healed, too! God loves me and He loves you and we are to praise God in all things, whether good or bad, for whatever trials we are going through either makes us grow stronger in faith and in the righteousness of our blessed Savior, Jesus, or we turn away from or refuse to believe and cast angriness towards Him instead of blaming satan where all blames lie because he comes to steal, kill and destroy our bodies when he can, but he cannot destroy our souls for our souls belong to God and it is up to each of us to make the right choice to choose Jesus or to choose satan. Jesus is love and goodness, while satan is hate and evilness; therefore, let us choose Jesus and have faith believing that we are His and He rules our lives for our best! May God Bless! Amen!

Ma Betty