St. Alphonsus Liguori
“I thank thee, O holy Faith; for thou teachest and assurest me that in the Divine Sacrament of the Altar, in that heavenly bread, bread does not exist; but that my Lord Jesus Christ is all there, and that He is there for love of me. My Lord and my All, I believe that Thou art present in the Most Holy Sacrament; and though unknown to eyes of flesh, by the light of holy faith I discern Thee in the consecrated Host, as the Monarch of heaven and earth, and as the Saviour of the world.”
Source: St. Alphonsus Liguori, Visits to the Most Holy Sacrament