They'd hardly walked out before the woman began breathing rapidly, became drenched in perspiration, and had a pulse rate of over 150 beats a minute. By the time Dr. Lown returned to the room her lungs had an accumulation of fluid. He asked the woman, who was clearly distraught, what was wrong. Dr. Lown tried to reassure her that such was not the case. According to her faith, be it was done unto her.
Faith is incredibly powerful.
It can release the very power of life, the power of God, in our lives. Or it can empower the Thief of life. Faith isn't magic. It is a principle of life like gravity, or thermodynamics, but we know less about it. In other words, his faith didn't release the power of God to heal him, but it did release the power of God to see him through.