Many churches and pastors today teach of healings and happiness as gospel. Some even go as far as to say something is wrong with you and your faith if you aren't perfectly happy and healthy. These teaching as so far from the real gospel of Jesus.
When so many follow after falsehoods about the gospel, Oswald Chambers in his year long devotional book "Utmost for His Highest," has helped me grow in my faith, with his simple and humble faith in the true gospel of Christ. He raises a great question in his Dec.2 entry:
"How can we say, "It could never be God's will for me to be sick?" If it was God's will to bruise His own Son (Isaiah 53:10), why shouldn't He bruise you? What shines forth and reveals God in your life is not your relative consistency to an idea of what a saint should be, but your genuine, living relationship with Jesus Christ, and your unrestrained devotion to Him whether you are well or sick."
Yes, Jesus, because of His compassion, healed the sick when He was here on earth, but like Billy Graham says:
"He fed the poor. He healed the sick, raised the dead, but that was not his purpose. His purpose was to go to the cross."
He came to suffer and die for us, so is it possible that God could sometimes choose not to heal, but use our sickness for His glory? I think so.
and Jesus said..."In the world you will have tribulation; but be of good cheer! I have overcome the world."