“The Eucharist is the source and summit of the Christian life.” Catechism of the Catholic Church, No. 1324.
“By the consecration the transubstantiation of the bread and wine into the Body and Blood of Christ is brought about. Under the consecrated species of bread and wine Christ himself, living and glorious, is present in a true, real, and substantial manner: his Body and his Blood, with his soul and his divinity (cf. Council of Trent: DS 1640; 1651) Catechism of the Catholic Church, No. 1413
“The mode of Christ’s presence under the Eucharistic species is unique. It raises the Eucharist above all the sacraments as “the perfection of the spiritual life and the end to which all the Sacraments tend.” In the most blessed Sacrament of the Eucharist “the body and blood, together with the soul and divinity, of our Lord Jesus Christ and, therefore, the whole Christ is truly, really, and substantially contained.” “This presence is called ‘real’ – by which is not intended to exclude the other types of presence as if they could not be ‘real’ too, but because it is presence in the fullest sense: that is to say, it is a substantial presence by which Christ, God and man, makes himself wholly and entirely present.” Catechism of the Catholic Church, No. 1374