Simple theory: Vorinism was founded by an Elsecaller

[Elsecaller_17.5]

Well first off I dont think it's at all a stretch to day proto-vornism was founded by Radients it's obvious from the emphasis on 10, the Heralds, and the Almighty/Honor/Tanavast.

But why specifically Elsecallers? Because the fundamental tenat of Vorinism is self improvement. This is practically identical to the theme of Elsecaller oaths "I will reach my potential."

I find it very ironic that Jasnah rejected Vornism on grounds of Atheism, but when you boil down Vorin ideals and her ideals (as demonstrated by her position in the Elsecallers) they are the same.

As a final note I'd like to emphasis that proto-vornism was founded by an Elsecaller. Its obvious its been through drastic changes.

Edited June 26, 2020 by Elsecaller_17.5
Typo

[Honorless]

Vorinism might also simply have been modelled after the Knights Radiant. The division of Orders inspiring the division of labour by choosing one's Calling

[Aminar]

Yeah. The search for Radiance is the search for self improvement. Elsecallers just have a more inwardly bent version than others. It even holds that Radiants have light eyes and that the caste system is based on that. I suspect it was founded initially to try to entice the Spren back after the recreance. Later records were tweaked to rewrite Vorinism into something older and bigger. 

[thejopen27]

I still don’t believe the Sunmakers propaganda about how bad the heirocracy was. I still think it was just a group of servants of radiant who tried to hold together order using some fabrials.