Nation and Ethnos (Ethnicity), as we perceive them today, became two sociological phenomena since the second half of the XVIII century, particularly after the French Revolution. Nevertheless, in Church circles and even more out of them, one can hear the criticisms on the Church’s expense who in present days „fell under the influence“ of these two phenomena and is in „imminent danger“ to fully embrace them. However, the problem is that these criticisms are based on tradition and history of the Church, referring to the time long before the emergence of today’s ideas of nation and ethnicity. But the topics which are new for the Church, must not automatically be labeled as noncanonical. This paper is an attempt to point out the fact that the Church, since its earliest times, was not opposed to the nation and ethnos as such, but simply, they were never subject for a discussion within the Church, nor has the Church seen the two phenomena as a potential problem. On the other hand, these two sociological phenomena, as we perceive them today, inevitably open up new questions for both the Church and Church organization, consequently this paper involves several relatively new canonical subjects which are in an immediate connection with the contemporary notions of nation and ethnos.