denominationalism

noun

de·​nom·​i·​na·​tion·​al·​ism di-ˌnä-mə-ˈnā-shə-nə-ˌli-zəm 

1

: devotion to denominational principles or interests

2

: the emphasizing of denominational differences to the point of being narrowly exclusive : sectarianism

Word History

First Known Use

circa 1855, in the meaning defined at sense 1