2.1 The sacrament gives to the church a ‘communion in the mystery of Christ,’ and thus the sacrament is a true sign of this mystery.
Matthew 18:20: ‘for where two or three are gathered in my name, there am I in the midst of them.’ John 14:21, 23: ‘They who have my commandments and keep them are those who love me; and those who love me will be loved by my Father, and I will love them and reveal myself to them … Those who love me will keep my word, and my Father will love them, and we will come to them and make our home with them.’
According to T. F. Torrance, Calvin meant by the term ‘signify’ as used of a sacrament, or the term ‘present,’ not merely that which recalls to memory, or that which symbolises a thing, but that which designates the thing itself, that which re‑presents a thing; thus the sacrament is an act of re‑presenting the same Word which is given in the Incarnation. ‘Kerygm is in the fullest sense the sacramental action of the Church through which the mystery of the Kingdom concerning Christ and His Church, hid from the foundation of the world, is now being revealed in history … in kerygma the same word continues to be ‘made flesh’ in the life of the Church.’
The very withdrawal of Jesus from visible and direct relation to the world casts the Church into an eschatological relation with Christ the head of the Church. The Church lives between the cross and the parousia and thus the original sacramental relation of the creature to the Creator in the hypostatic union (Incarnation) is now re‑presented through the enactment of the life of the Church itself. But in this re‑presentation the full presence of the parousia is screened, permitting the Church to have a genuine history in relation to the world. In God’s revealing to and through the Church in Jesus Christ, God also is concealed in order to be present, not merely as another ‘presence’ alongside the existence of others, but in and through their existence.
Here is the danger of idolatry in the sacrament – ‘The call to worship can be the temptation to idolatry’, said Barth, but this is a call which cannot be avoided. The work and sign of Christ’s presence is not frustrated by unbelief, however, precisely because the re‑presentation is governed from the side of divine action, ‘offence can be taken’ through the substitution of the sign for that which is not signified. This danger of ‘offence’ seems to be greater for one who stands within the church than the one who comes in from without, and may actually be an ‘unbeliever’ in the church’s eyes (cf. 1 Cor 14).
 Cf. Thomas F. Torrance, Conflict and Agreement. Vol. 2 (London: Lutterworth Press, 1960), 140‑1.
 Torrance, Conflict, 158‑9.
 Karl Barth, Church Dogmatics II/1 (eds. G. W. Bromiley and T. F. Torrance; trans. G. W. Bromiley; Edinburgh: T&T Clark, 1969), 55.
 Barth, CD II/1, 55.
 Barth, CD II/1, 55‑6.