St. Cyril of Jerusalem, pray for us. Lord Jesus Christ have mercy on us all. Amen
St. Cyril’s teaching about the Blessed Sacrament is of the first importance, for he was speaking freely, untrammelled by the “discipline of the secret”. On the Real Presence he is unambiguous: “Since He Himself has declared and said of the bread: This is My Body, who shall dare to doubt any more? And when He asserts and says: This is My Blood, who shall ever hesitate and say it is not His Blood?” Of the Transformation, he argues, if Christ could change water into wine, can He not change wine into His own Blood? The bread and wine are symbols: “In the type of bread is given thee the Body, in the type of wine the Blood is given thee”; but they do not remain in their original condition, they have been changed, though the senses cannot tell us this: “Do not think it mere bread and wine, for it is the Body and Blood of Christ, according to the Lord’s declaration”. “Having learned this and being assured of it, that appears to be bread is not bread, though perceived by the taste, but the Body of Christ, and what appears to be wine is not wine, though the taste says so, but the Blood of Christ . . . strengthen thy heart, partaking of it as spiritual (food), and rejoice the face of thy soul”. It is difficult not to see the whole doctrine of Transubstantiation in these explicit words. Confirmation is with blessed chrism: “As the bread of the Eucharist after the invocation of the Holy Ghost is not bread, but the Body of Christ, so this holy myrrh is no longer simple, as one might say, after the invocation, but a gift of Christ and capable by the presence of the Holy Ghost of giving His divinity” (ii, 4).
Taken from New Advent