What is essential to remember, here [in the thought of St Irenaeus], is, on the one hand, the double movement of the Father who sends the Spirit on creation through the Son, but also of the Spirit who returns and brings the creature back to the Father, also through the Son. The Son will always be the mediator in all things; man’s entire life, his most incarnate, most fleshly human existence, will be summoned and made capable of being transparent to the action of the Spirit. Consequently, the Holy Spirit knows no boundaries in His work of permeating, of penetrating, precisely, this flesh or this human being He must soften, which He must constitute into one bread, one body, the Body of Christ. … It is the same action of the Holy Spirit on the Son and on the Church; it is the same action of the Holy Spirit in the sacraments and in man himself. Man too, to the degree that he becomes conformed to Christ, in the Church, through the Holy Spirit, becomes, in turn, “sacrament”: he becomes a sacrament of the new life, which means that his body rediscovers why it was created. The totality of the human psycho-physical composite, our entire created reality is capable of being penetrated, of being filled with the divine life. If the sacraments are symbols, if they are signs, they are this because the human body, man’s natural being, is this in the first place. I would call this the anthropological finality, and the continuity of the sacraments in the life and in the building up of the new man.
Boris Bobrinskoy, The Mystery of the Trinity: Trinitarian Experience and Vision in the Biblical and Patristic Tradition (Crestwood, N.Y.: St Vladimir’s Seminary Press, 1999) 205-206.