There's this #CHH rapper (that's #Christian #HipHop for the uninitiated), #DonReady, I believe, who recently got diagnosed with some form of serious cancer. He posted on #Instagram and said that after praying, he heard a word from God saying that despite the doctors' assessments, he would in fact be healed, and asked that others pray with him.
While everyone in the community was (and still is) saying "rah rah" and "amen", I wanted to scream in response. You cannot guarantee that God will heal you, and it is, I would say, very likely blasphemous to say that God told you He would heal you unless you heard His audible voice.
Christians die from starvation and cancer, and it's not out of lack of faith, my friends. We are to trust in God, not in what God can do for us. We are called to rest in God's will, not live in a delusion that God's will is going to be whatever we want for our own lives.