The Huffington Post, Matthew L. Skinner explores why "Advent is dangerous":
The impulses behind Advent should alarm those who are overly enamored with the current system (who probably number more than 1 percent), as well as any others who are overly confident in their ability to engineer what's best for the world.
Advent expresses the insistence that all is not right in our societies. That's a dangerous expression. Stoking hopes for a new world order, for justice to be for all, usually implies that old systems, governments and loyalties aren't what they're cracked up to be.
Notice: The transformation anticipated in Mark 13:24-37 is such a monumental and all-encompassing upheaval, its description must resort to symbolism. The symbolism is unnerving, even though it was familiar to ancient audiences. It suggests that, in the face of the God's desires coming to full fruition, every other power (symbolized by sun, moon and stars) receives notice and sees its light go out. No aspect of human existence goes untransformed when God enters in for good.
The claims of Advent should rattle all who benefit from exploitative and domineering forms of power. This means a lot of us, of course.