As Catholics, the Eucharist is the Source and Summit of our Faith.  The Catechism states:

"The Eucharist is "the source and summit of the Christian life." ¹³⁶ "The other sacraments, and indeed all ecclesiastical ministries and works of the apostolate, are bound up with the Eucharist and are oriented toward it. For in the blessed Eucharist is contained the whole spiritual good of the Church, namely Christ himself." -CCC1324

The Eucharist is the Body, Blood, Soul and Divinity of Jesus Christ.  It is the greatest Sacrament, as explained in the Catechism -

"The other sacraments, and indeed all ecclesiastical ministries and works of the apostolate, are bound up with the Eucharist and are oriented toward it." -CCC 1324