Adversity creates or rather requires reaction. This reaction builds strength and stamina and character. Each person experiences adversity for this purpose. If life were easy and blissful, decisions - hard decisions, would not be forced to be made. These essential decisions must be made in order for there to be soul strengthening.
In the parable of the sower, we see that some seeds sprout readily and grow tall - quickly, soon to be withered in the sun, not having the requisite strength and fortitude to withstand vicissitudes. Each person is like a plant. The good gardener - the Thought Adjuster, directs the tilling of your soil, the fertilization of your roots, the rain to fall, the wind to blow, and the sun to shine. All this is done through the action of angels among others. He sees to it that His beloved child receives what is needful for the best growth of his soul. Adversity, even calamity, can be part of the nurturing process. The blessing of these seeming calamities may only be seen through hindsight and are not apparent to the growing seed-child. The good parent insures proper medicine for any illness, proper exercise to grow and nourishment to maintain robust health. Each child requires differing remedies and different exercise. By exercise, I am referring to robust life activity, mental and physical. In order to meet the challenges of life each person must have experienced a certain hardship factor. In knowing that past hardships have been overcome strengthens the mind/soul for future hardship or mind conflict, which also must be grappled with.
This "I can do" attitude is important and cannot develop without having done. Therefore, adversity, small and great, befalls us all and must be overcome and grappled with individually in order to build a strong and reliable soul.