Sacraments of Initiation
As the Catechism of the Catholic Church teaches us "The sacraments of Christian initiation — Baptism, Confirmation, and the Eucharist – lay the foundations of every Christian life. The sharing in the divine nature given to men through the grace of Christ bears a certain likeness to the origin, development, and nourishing of natural life. The faithful are born anew by Baptism, strengthened by the sacrament of Confirmation, and receive in the Eucharist the food of eternal life. By means of these sacraments of Christian initiation, they thus receive in increasing measure the treasures of the divine life and advance toward the perfection of charity."
Catechism of the Catholic Church #1212.
Baptism
The origin and foundation of Christian Baptism is Jesus. Before starting his public ministry, Jesus submitted himself to the baptism given by John the Baptist. The waters did not purify him; he cleansed the waters. . . . Jesus did not need to be baptized because he was totally faithful to the will of his Father and free from sin. However, he wanted to show his solidarity with human beings in order to reconcile them to the Father. By commanding his disciples to baptize all nations, he established the means by which people would die to sin – Original and actual – and begin to live a new life with God.
In Baptism, the Holy Spirit moves us to answer Christ's call to holiness. In Baptism, we are asked to walk by the light of Christ and to trust in his wisdom. We are invited to submit our hearts to Christ with ever deeper love.
~from the United States Catholic Catechism for Adults
Confirmation
Strengthened by the Spirit, Called to Action.
At Confirmation, our faith and membership in the Body of Christ is confirmed, or strengthened. In the Rite of Baptism, we become new members of the Body of Christ, but our journey does not end there. The decision to be baptized is followed by continued growth, learning, and witness as members of the Body of Christ. Our desire to continue to grow and develop as Christians finds expression in Confirmation, when we renew our baptismal promises and receive in a new way the gift of the Holy Spirit, which strengthens our “bond” with the Church and its members
(CCC, no. 1316, and Pope John Paul II, Redemptoris Missio [On the Permanent Validity of the Church’s Missionary Mandate], no. 26).
Holy Eucharist
In the Eucharist Christ fulfils his promise to be with us "always, until the end of the age" (Mt 28:20). As St. Thomas Aquinas wrote, "It is the law of friendship that friends should live together. . . . Christ has not left us without his bodily presence in this our pilgrimage, but he joins us to himself in this sacrament in the reality of his body and blood" ( Summa Theologiae, III q. 75, a. 1). With this gift of Christ's presence in our midst, the Church is truly blessed. As Jesus told his disciples, referring to his presence among them, "Amen, I say to you, many prophets and righteous people longed to see what you see but did not see it, and to hear what you hear but did not hear it" (Mt 13:17).
In the Eucharist the Church both receives the gift of Jesus Christ and gives grateful thanks to God for such a blessing. This thanksgiving is the only proper response, for through this gift of himself in the celebration of the Eucharist under the appearances of bread and wine Christ gives us the gift of eternal life.