If a friend were having a nightmare in which he thought he was being chased by an angry bear, would you need to find a way into his dream and give him a gun so he could save himself? Obviously, that wouldn't be the answer to his problem. But let's suppose it was possible to do this. What would be the result? Simply this: you would have two people, in effect, dreaming about a dangerous bear. And neither of them would be any closer to the solution to the problem. Something would still need to wake them up from the dream.
Most people are conscious of having dreamed now and then, so we are aware of how real dreams seem to be. But even if a dream has had a photorealism quality to it, it remains entirely a mental event, not a physical one. When we wake up, we simply make a mental adjustment, recognizing that we were dreaming.
It's good to remember this when we consider these statements from Science and Health with Key to the Scriptures by Mary Baker Eddy: "To the Christian Science healer, sickness is a dream from which the patient needs to be awakened. Disease should not appear real to the physician, since it is demonstrable that the way to cure the patient is to make disease unreal to him." Science and Health, p. 417. And, "Keep distinctly in thought that man is the offspring of God, not of man; that man is spiritual, not material; that Soul is Spirit, outside of matter, never in it, never giving the body life and sensation. It breaks the dream of disease to understand that sickness is formed by the human mind, not by matter nor by the divine Mind." Ibid., p. 396.