Metropolitan Hilarion of Volokolamsk
The Augustinian understanding of the “efficacy” of the sacraments was never fully accepted in the Orthodox Church. Such an understanding of the sacraments is unacceptable for Orthodox tradition, for it is an understanding in which the grace inherent within them is considered autonomous, independent of the Church. The sacraments can be performed only within the Church, and it is the Church that bestows efficacy, reality, and salvation on them. (Orthodox Christianity Vol. II: Doctrine and Teaching of the Orthodox Church, p. 405)
