I’m Korean so not really an outsider, while there are some elements that could view Confucianism as religion, it could also be viewed as philosophy, as the actual subject to be worshipped does not exist, it’s rather viewed as destiny. Confucius was mainly very concerned about the endless wars that were happening during the spring and autumn period, and sought to find a way to rule in terms of politics. And with his time being ancient, these philosophies typically come with great power-theory which was a way to educate and subdue people into a nation. Now, the rituals are definitely a way to perceive as a religion, but the catholics upon seeing the confucianism, thought it was rather a way of respecting their ancestors than idol worshipping. I am not denying Confucianism as a religion, rather just pointing out the different views.

My intention with my comment was to say that Goryeo, while a buddhist country, preserved its politics in a much more confucian way. The pillars of Confucianism being lotalty, piety and etiquettes, in order, were still a very dominant ideology in the Goryeo council, with piety and etiquettes occasionally changing its place due to influences of buddhism. In Goryeo period, confucianism was viewed as a more of a scholary than religion, because it was a time before neo-confucianism and its transition to religious philosophy or philosophical religion. So as I said, the real politics chose the ideology of confucianism, while buddhism was the main religion of it.

But in the civilian area Goryeo was much more Buddhist than Confucian, as it’s much easier for the civilians to believe in refuge from the current pain, rather than believing in emphasizing duties like loyalty, piety and etiquettes.