The bread that you see on the altar is the Body of Christ as soon as it is sanctified by God’s word. The chalice, or better what is contained in the chalice, is the Blood of Christ as soon as it is sanctified by God’s word.
What wonderful majesty! What stupendous condescension! O sublime humility! That the Lord of the whole universe, God and the Son of God, should humble Himself like this under the form of a little bread, for our salvation.