The sacrament is made to carry with it an objective force, so far as its principal design is concerned. It is not simply suggestive, commemorative, or representational. It is not a sign, a picture, deriving its significance from the mind of the beholder. The virtue which it possesses is not put into it by the faith of the worshipper in the first place, to be taken out of it again by the same faith, in the same form. It is not imagined of course in the case that the ordinance can have any virtue without faith, that it can confer grace in a purely mechanical way. All thought of the opus operatum, in this sense, is utterly repudiated. Still faith does not properly clothe the sacrament with its power. It is the condition of its efficacy for the communicant, but not the principle of the power itself. This belongs to the institution in its own nature. The signs are bound to what they represent, not subjectively simply in the thought of the worshipper, but objectively, by the force of a divine appointment.
J.W. Nevin, The Mystical Presence, pp. 67-68 (emphasis added)
This power belongs to Jesus, who has so ordained to work and minister his grace through the institution.