An outward Church is the necessary form of the new creation in Christ Jesus, in its very nature; and must continue to be so, not only through all time, but through all eternity likewise. Outward social worship, which implies, of course, forms for the purpose, is to be regarded as something essential to piety itself. A religion without externals, must ever be fantastic and false. The simple utterance of religious feeling, by which the spirit takes outward form, is indeed, not for something beyond itself, but for the perfection of the feeding itself. Forms, in this sense, not as sundered from inward life, of course, but as embracing it, enter as a constituent element into the very life of Christianity. As a real, human, historical constitution in the world, the outward and inward in the Church can never be divorced, without peril to all that is most precious in the Christian faith. We have no right to set the inward in opposition to the outward, the spiritual in opposition to the corporeal, in religion. The incarnation of the Son of God, as it is the principle, forms also the true measure and test, of all sound Christianity, in this view. To be real, the human, as such, and of course the divine also in human form, must ever externalize its inward life. All thought, all feeling, every spiritual state, must take body, (in the way of word, or outward form of some sort,) in order to come at all to any true perfection in itself. This is the proper, deep sense of all liturgical services in religion. The necessity here affirmed in universal. The more intensely spiritual any state may be, the more irresistibly urgent will ever be found its tendency to clothe itself, and make itself complete, in a suitable external form. Away with imagination, then, that externals in Christianity (including the conception of the visible Church itself,) are something accidental only to its true constitution, a cunningly framed device merely for advancing some interest foreign from themselves. To think of the Church, and of Christian worship, as means simply to something else, is to dishonour religion itself in the most serious manner.
-John Williamson Nevin, Preface, The Mystical Presence: A Vindication of the Reformed or Calvinistic Doctrine of the Holy Eucharist.