So, how is this dialectical? If we just use the medieval notion of dialectics, which reduces to the way that different ideas change with context, and the introduction of other ideas, then the interplay of the individual's will and the prompting of the spirit constitutes a small battle of ideas. (This is probably it, given the mess that follows.)
In the Hegelian context (my reading of the moment, not an expert, or even good at it), what is sublated out is perhaps the individual's notions of their own will and the notion of what the holy event would be. These two things, in the negation (which is done by the individual) then suggest a larger world of the possible actions that might result. I think that I might (1) buy chocolate ice cream, or I might (2) get some healthy fruit, and these two impulses illuminate the larger class of things I could get to eat. The second is further sublated into the notion of action transformed into more beneficial action. So I now have a world of possible things to get for dinner, and, further, a world in which the things that are better for me prevail. And this is the sphere of the spirit's action: the foreseeable events, and the ways in which they could go well rather than badly.
By willing the collaboration with grace, the individual is negating their own impulse, while holding onto these spheres (c-classes) of possible actions of a certain kind. And they are then open to something else happening within these spheres. But the negation of their particular impulse (chocs, fruit) is valuable in that it brings these worlds of possible experience into their consciousness. They are negated only because it was the individual that thought of them, so perhaps it's the individual that is sublated out as the one who acts well, past the particularities of their initial impulses. The spirit is not the eventual action, but just the movement from that initial particularity, to the universal, and then the realm of possible alternate particularities. The spirit is not in that realm of possible actions, but the fact of the movement away from my initial particularity to that expanded realm. The movement, not the substance. Which perhaps brings it much closer to the things that I can will, and prompt by my actions.
Frankly, I'm no dialectician. Which, seen dialectically, is much less of a fault.