It is a general insight (and one that I have accepted) of Rudolf Steiner, Owen Barfield and William Arkle; that evil in the world can be understood as having an educative purpose. In essence this mortal life is 'for' theosis (becoming more divine); meaning for experiencing and learning aiming at an eternal resurrected life in Heaven.
Evil is tolerated because it may be necessary for this purpose. But such a general explanatory 'model' is Not understanding; understanding can only come from learning the role of evil in our own life (or, perhaps, the life of someone loved by us).
Thus it is a foolish and arrogant error to try and explain what specific role some named evil has-played or is-playing in another-person's life, or in the lives of groups of people who are strangers or known only at secondhand (from hearsay, the mass media or history books; or even from fictions and lies) - families, tribes, races, nations, or mankind as a whole.
What I will do here is simply to explain ways in which the creeping totalitarianism of the modern West has had a positive and educational role in my own life. This can be summarised briefly: the fact that totalitarianism has been increasing throughout my life has prevented me from living-out a worldly life; has prevented me from living a life dedicated to mortal life.
In different words; the ratchet of totalitarianism disrupted every accommodation and adjustment I made with The World, continually preventing me 'settling' into contentment; and thereby it pointed me in the direction of realising that my life was ultimately not 'about' my happiness in this world.
I am, by nature, someone who finds totalitarian bureaucracy extremely unpleasant. I am a natural romantic and individualist. I have no desire to be a leader, but I hate to be a cog in a machine. I am not a 'joiner' and tended to fall-out, or become disaffected, with almost any group; sooner or later (apart from my family).
Yet I began life with an idealism directed at certain institutions such as the profession of medicine (being 'a doctor') and the universities. I loved the arts of literature and music. I was a proud member of my schools, and medical school; and did well at both.
I was also dedicated to the ideals of these institutions: education, science, medicine etc. My dreams were substantially of fulfilment through success in these institutions - envisaged as as these institutions had been during the period of my youth, and earlier as I knew them through reading and the older generation. I craved the special status that comes from recognition by the peer group of those I admired.
But as I moved forward and upward through these institutions, they were always changing - getting worse overall, always in the direction of more bureaucracy, greater surveillance, tighter and more detailed control. They became more hostile to the individual, to the eccentric, to the ideals - and more merely instances of the generic bureaucracy (the Iron Cage of Weber, the Black Iron Prison of Philip K Dick).
As soon as I achieved a position to which I had aspired (and this did happen, several times); that situation would begin to collapse, would begin to be corrupted by the (universal) forces of totalitarian bureaucracy.
No sooner did I plant my feet on some ledge of firm and pleasant ground, than that ground would begin to crumble under my weight. I would very soon feel a need to seek some other niche.
My early and immediate response to recognising the creeping evil was political. To try and 'change the world'.
My implicit assumption was that there was no other existence than this mortal world, and that the solution to The System of bureaucracy was (must be) a better system. Therefore I thought (as most people do) in terms of a political solution. I would fight the changes - on the confident assumption that something significantly better was possible.
I went through one after another 'possible' political solution, and pursued my political goals as most intellectuals do: through joining a 'party' or pressure group, conversation, writing, lecturing, and a bit of 'organising'.
My covert assumption was that institutions - society itself - could (in principle at least) be improved to the point that the major problems would be eradicated sufficiently for a worthwhile life; and that the positive rewards would be sufficiently great that life (my mortal life in particular) would be justified.
In sum: that a meaningful and purposive life would be attainable.
I can now perceive that this was a foolish, vain aspiration - that the reality, the bottom-line, the existential nature of mortal life (with its intrinsic change, decay, disease, and death understood as annihilation) does not, cannot - therefore will not - suffice.
But so long as there was some (albeit dwindling, as the years went by) worldly, political-social avenue left unexplored; so long as it looked theoretically-possible that the totalitarian bureaucracy might be halted and compelled into reverse - for so long did I fail to understand the nature of life and the perspective of real-reality.
It actually, in practice, I needed the ever-worsening, ever-greater unreality and evil of The System, The Matrix, The Establishment - to exhaust one after another and all of my false and feeble daydreams, wishful thinkings, simplified models and half-insights - before I eventually learned the necessary lessons concerning the true nature of reality and hope.
Therefore, this is an actual example of how the long-term personal effect of something evil - indeed the long-term triumph of purposive evil across the world - actually led to learning something vital; and a thing that a more gratifying, easier, more-successful life in a better world would Not have taught me.
If things had gone 'according to plan' - if I had had the kind and degree of worldly success and gratification that I envisaged for myself as a youth, and if I had found my tastes of such things to be as subjectively and sustainedly-gratifying as I expected - then I would almost certainly have lived my life in a delusory dream, and died without ever noticing that I was engaged in a demonic project of self-centred, hedonistic, short-termist, manipulative and (ultimately) nihilistic evil.
Thus if I had achieved something-like my dreams -and if these dreams had really worked; then I would have wasted my mortal life.
I would have been 'taken' by sudden death directly from a euphoric state of pleasurable self-congratulation and confronted with a Jesus to whom I regarded myself as greatly superior; and whose offer of Heavenly life everlasting would have had little attraction (involving as it does, a loving embrace of the divine project of creation).
I might well have rejected Heaven on the basis that I was existentially satisfied by living conceived as here-and-now self-gratification as the highest ideal; all I would have wanted was that this be continued until... nothingness.
In sum, without the sustained and adverse environment of creeping totalitarianism to sabotage my tin-pot schemes of immediately pleasurable indulgence; I would very likely have stayed on the broad and pleasant road to Hell - which I had sketched-out in my youth.
And this - it seems to me, is a specific and exact instance of why (and how) we need evil in order to reach good.
Of course this instance does not in any way justify the evil in your life; let alone some other person's life (known or unknown) - nor any great masses of people who might be envisaged. That is for you to discover for yourself - each and individually.
But you can be sure that your actual life is trying to tell you what you most need to know; year-by-year, day-by-day, hour-by-hour trying to break-down your resistance to such knowledge. Even so obtuse a person as myself eventually crumbled under this pressure - but it took a great deal of such pressure, and for a long time, before I did.
For me - this is one reason why my world was adverse; and why there needed to be so much adversity and of that particular type.