The Marks of the Church
For the Protestant Reformers there were two notae or “marks” of the church: the preaching of the word and the administration of the sacraments.
Hendrikus Berkhof, in his Christian Faith, speaks of the following notae:
(i) instruction (i.e., catechetics)
(ii) the washing
(iii) the sermon
(iv) the discussion
(v) the meal
(vi) the diaconate
(vii) the meeting
– – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – –
(viii) office
(ix) church polity (church order)
Berkhof maintains that these lattermost two serve to make the other seven operative. [“Operative”, not “effective”: Jesus Christ alone, in the power of his Spirit, makes (i) through (vii) effective or “effectual”.]