He believed that denominationalism would prove to be the mark of the beast.
From the en.wikipedia.org
Conversion is the point where religious rigidity, Israeli politics and diaspora denominationalism clash.
From the economist.com
These differences can be so serious that they form a principal reason for division i.e., denominationalism.
From the en.wikipedia.org
Alexander Campbell had concerns that holding conventions would lead the movement into divisive denominationalism.
From the en.wikipedia.org
The choice of a Presbyterian to head the new college communicated that the institution would emphasize Christian education over denominationalism.
From the en.wikipedia.org
These groups attempted to transcend Protestant denominationalism and orthodox Christiancreeds to restore Christianity to its original form.
From the en.wikipedia.org
Denominationalism is an ideology which views some or all Christian groups as being, in some sense, versions of the same thing regardless of their distinguishing labels.
From the en.wikipedia.org
More examples
Sectarianism: a narrow-minded adherence to a particular sect or party or denomination; "he condemned religious sectarianism"
The tendency, in Protestantism, to separate into religious denominations or to advocate such separations