Surely we have lots of grief as human beings.
Many would look at Christians as having their own unique sources for grieving (as well as rejoicing) - there's grieving over the lost and what they do...
And, of course, we need an ethical way to promote goodness (if there is such a thing) and good deeds (or at least the cessation of systemic evil, systemic oppression, and systemic wrongdoing) without communicating error (false thoughts - a reason fiction has been suspect in many areas).
The idea of everyone going to hell is a pretty grievous concept, even if the vast majority of others weren't ever met (let alone known) to us.
The idea of the Holocaust and genocide is pretty awful. Thee ideas that activist groups everywhere focus on - one by one - human slavery, war, rape and incest, and all kinds of wrong doing - are pretty atrocious and grievous.
The recognition of predation in nature itself is pretty grievous, as is the stubborn refusal of many humans to rightfully lift themselves out of that predatory system, despite our human abilities and our lack of a metabolic requirement for eating animals. Yet, that's the world we find around us, and for some not-fully-understood reasons, we're becoming free of that predatory cycle. In grief, we also have reason to rejoice, though we continue to grieve - and work.
In thinking about Grief, Grieving, and the Grievous, we ought (I think) to recognize that Grief, Grieving, and the Grievous are three distinct (though inter-related) realities. We can work on the grievous, about which we and others grieve. We may be able to make some systematic headway or progress in addressing the grievous, though (in reality) it's pretty far advanced, and religious literature everywhere DOES talk about "that hideous strength" (as even C. S. Lewis does in his Trilogy). There is the grieving we do, sometimes with an object, and sometimes not - sometimes because of loss or even a fear or sense or anticipation of loss (such as one's fear of aging and age-related decline). And (I guess) talking about "grief" is talking about the common experience of grieving.
But watch, how quickly it all becomes oh so personal, as we can expect it would be.
One thing is sure - in times of others' grief, many of us are not very good at consolation... and grief CAN turn to anger - long-standing anger. If we face that "inner turn", hopefully we'll learn to channel our energies constructively, not destructively.