Flesh and Blood

Non est humano aut saeculi sensu in Dei rebus loquendum, neque per violentam atque imprudentem praedictionem; coelestium dictorum sanitati, alienae atque impiae intelligentiae extorquenda perversitas est. Quae scripta sunt legamus, et quae legerimus intelligamus: et tum perfectae fidei officio fungemur. De naturali enim in nobis Christi veritate quae dicimus, nisi ab eo didicimus, stulte atque impie dicimus. Ipse enim ait, Caro mea vere est esca, et sanguis meus vere est potus. Qui edit carnem meam et bibet sanguinem meum, in me manet, et ego in eo. De veritate carnis et sanguinis non relictus est ambigendi locus. Nunc enim et ipsius Domini professione, et fide nostra vere caro est, et vere sanguis est. Et haec accepta atque hausta id efficiunt, ut et nos in Christo, et Christus in nobis sit. Anne hoc veritas non est? Contingat plane his verum non esse, qui Christum Jesum verum esse Deum denegant. Est ergo in nobis ipse per carnem, et summus in eo: dum secum hoc, quod nos sumus, in Deo est. Sanctus Hilarius Pictaviensis, De Trinitate, Liber VIII

Not in a human or worldly sense must we speak of  the things of God, nor must violent and unwise preaching extort from the soundness of celestial words perversites of impious understanding. Let us read what has been written, let us understand what we have read, and so let us fulfill the office of perfect faith. For concerning what we say of the reality of Christ's nature within us, unless we have been taught by Him, we speak foolishly and impiously. For He says, 'My flesh is meat indeed, and My blood is drink indeed. He that eats My flesh and drinks My blood abides in Me, and I in him.'1 Concerning the truth of the flesh and blood there is no room for ambiguity. For now from both the declaration of the Lord Himself and our own faith, it is true flesh and true blood. And these, eaten and drunk, make it so that both we are in Christ and Christ in us. Is not this true? Certainly it may strike them not to be  true who deny that Christ Jesus is truly God. He therefore Himself is in us through the flesh and we in Him, while together with Him our own selves are in God. Saint Hilary of Poitiers, On The Trinity, Book 8 1 Jn 6.56