Mark of the Church
Submission to the Word is thus in the deepest sense the sole mark. But, of itself, this one mark divides into three when one recalls that each visible church must be the gathering and the mother of believers at the same time.
Geerhardus Vos, Reformed Dogmatics, ed. and trans. Richard B. Gaffin Jr., vol. 5 (Bellingham, WA: Lexham Press, 2012–2016), 24.