Do I have the testimony even when I do not receive the miracles that I want? That would be unconditional discipleship. In Matthew 8, Jesus has just finished preaching the sermon on the mount and the comes out of the mountain being followed by this giant multitude of people. He's finished teaching the people, and now he's going to demonstrate it in the healing of the leper.
The leper says: "Lord if thou wilt, thou canst make me clean."
He recognizes the power of the Lord, but has total submission and trust in the Lord. Simply in saying "if thou wilt," we can see that the leper was willing to accept a fate of pain and suffering for the rest of his life, if that was the Lord's will.
Jesus Christ doesn't shy away from interacting with broken and diseased people. Healing miracles have two components: physical and spiritual. The obvious change in the leper was that he didn't have to suffer that pain anymore. But does that mean that he will never ever experience any other type of physical ailment for the rest of his life? No. All physical miracles will eventually end in death. The spiritual healing and lesson that comes from a healing is never-ending. That's why disease is used as a metaphor for sin so many times in the scriptures. While physical healings are important, the most important type of healing comes from the cleansing power of the Atonement.
Elder Rasband said: "We get a glimpse into our Heavenly Father’s character as we recognize the immense compassion He has for sinners and appreciate the distinction He makes between sin and those who sin. This glimpse helps us have a more “correct [understanding of] his character, perfections, and attributes” and is foundational to exercising faith in Him and in His Son, Jesus Christ. The Savior’s compassion in the face of our imperfections draws us toward Him and motivates us in our repeated struggles to repent and emulate Him. As we become more like Him, we learn to treat others as He does, regardless of any outward characteristic or behavior."
We can be going through a turbulent physical time in our lives, outside of our control, and still remain calm inside knowing that we are in the ship with Jesus Christ who is only concerned with helping us. So yes, a thousand times yes, I can believe that he knows enough to do what's best for me.