Healing by the laying on of hands, by passes, by touch, etc. is not just an interaction of the energy of the medium and spirit action, the medium can influence the healing affect.
Pain opens our eyes, awakens our feelings, short or long-term, it forces us to reflect, to change our attitude, to really consider our situation ...
Despair is the height of pain, be it physical or moral. Understanding the rules of evolution is the best antidote to this feeling.
The understanding of the evolutionary process, always equivalent and eminently fair for all, helps us to face the hard and complicated circumstances that Life puts in our path to help and to test, also, our evolutionary reality. To many, it may seem strange that suffering is so many times the way that teaches us to improve ourselves. It would give the impression that such teaching would be better pursued voluntarily; but, we are still far from learning with the sole impulse of our [own] volitional capacity.
Let's end with some glowing words of encouragement from the great [named and known as the “Apostle of Spiritism”] Léon Denis (from his book After Death, Conclusion):