Is there anything in Jewish conceptions that pain and suffering are good for the soul or purify the soul in some way?

There are many different types of and approaches to suffering, all from valid Jewish sources. The general approach to pain and suffering is that we would rather be without them, we don’t seek them in any way, yet if they do come, we should know they have a purpose, so we gain from them and know how to treat and live with them. As for the purpose of the suffering, different reasons are brought: They are to atone for sin; They are the means to purify one material existence and come closer to G-d; They are a sign of the love of G-d to man; and more. In the Encyclopedia of Jewish Medical Ethics (vol. 3 p. 143-182), there is a whole entry on this topic. I have never understood the Christian approach either; though I must say I have never tried to...