I know you can't see me, but I'm scratching my head. So wait, how again does the sacred relate to godhood, in simple terms that even I would understand? If I understand what you're saying, then you and I have inverse opinions in that most things considered "sacred" are considered so because of the diety they are related to, not the other way around.
There is no chicken-egg dichotomy. Whether being sacred makes a god or whether a god makes things sacred isn't really an issue. In the simplest terms, a god is a sacred thing. There is the Profane; transient every day life. There is the Sacred, the reality that is true and set apart. The profane and sacred have as sharp a distinction as earth and sky. They are different planes of existence. A being which is sacred is a deity. Profane life takes on value only by emulating the models set by the sacred, typically by these deities, as it's they who found the structure and purpose of the universe, or give meaning to what would otherwise have none.
In TES, there is a distinction between Mundus, the mortal realm and Aetherius, Oblivion and the God-planes. They are set apart. The spheres of aedra and daedra represent forces, emotions and ideas, and they are expressions of enshrined values. No matter how human their appearance, they're as fundamentally different to us in a way that, say, another race isn't, because of the
meaning and
feeling they inspire. In these terms, Vehk is an appearance of the sacred into the profane.
An Axis Mundi is a connection from the profane world to the sacred. It also acts as a sort of compass point. "There lies the sacred and we should orient ourselves towards that." The nomads I talked about carried it with them, so they were always connected. Most of the time it's fixed. It could be a tree, like Yggdrasil. It could be a mountian, like mount Olympus. It could be an object, like the ka'aba or the Christian cross. It could be a building, like a pyramid. It could be a tower, like... yes, like
those. The Axis Mundi is sometimes called the Center of the World. This is also what Vehk means when he says "
The Sharmat sleeps at the center. He cannot bear to see it removed, the world of reference." and
"There is no true symbolism of the center. The Sharmat will believe there is. He will feel that he can cause years of exuberance from sitting in the sacred, when really no one can leave that state and cause anything more but strife." Vehk is a demigod and dwells in both the profane and the sacred worlds, blurring these two distinctions, so presumably is his own reference point.
For more info, http://en.wikipedia.org/wiki/Mircea_Eliade#Sacred_and_profane
So... Vivec DID (try to, at least) kill Lord Neravar?
Im confused now....
He's speaking to the Nerevarine, not Lord Nerevar. But he did kill Lord Nerevar, yes, both hiding a message in the Sermons and explaining it openly at the Trial of Vivec. There are other threads exploring that.