My God-Machine is a conspiracy, a system whose influence has grown with the rise of mankind itself so it's only invisible because we lack the baseline any more to tell what the world would be without it. It was first discovered then further advanced through the ages by an elevated pantheon of small Gods able to harvest a particular resonance from human beings to further their causes. It is thus an invention, as it did not originally exist; it's still evolving after a fashion but only internally, into an ever-greater refinement of itself.
Among those Gods that birthed it some have waned in power and are now extinct (or are now barely able to function due to extended starvation) while others are patrons of popular notions and are thriving, so they're doing everything in their power to further and integrate their agenda on the world even more. They are using their apostles among the populace, driven by Angels, to achieve this; occasionally a champion rises around whom they can build - most of our most celebrated historical figures were numbered among them.
Like liches they maintain the status quo because if they fear one thing above all others it is a true paradigm shift, something unprecedented that'll prove incompatible with their system, bringing an end to their reign. Therefore everything has to be a derivative, a product of something which came before, so that any radical turn must be suppressed, diverted from its course and stalled to irrelevance.
Time is their ultimate tool since it's the one inexhaustible resource they have left; their failures are buried in its depths (Atlantis, Lemuria, the Library of Alexandria, long-gone Empires, etc). My campaign would be based on exploration of ancient resources as characters hunt down what they're not supposed to find in whatever it is these Gods feared in the first place enough to take corrective measures, while being tempted with elevation to the status of champions or even Godhood itself themselves once they start getting too near to dangerous truths. I'd also throw some dilemmas for good measure - would they risk humanity realizing they've been played for millennia? Would they care ?
... That's what I got.