The Eucharist is "the source and summit of the Christian life." (Catechism of the Catholic Church #124) It is the source of the Christian life because the Most Blessed Sacrament of the Eucharist is Christ himself, body, blood, soul, and divinity.
"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." (St. Francis of Assisi).
Preparation for First Eucharist is also a wonderful opportunity for parents to refresh understanding, and strengthen their devotion to this Most Blessed Sacrament, in which Christ is truly present in a unique and powerful way.