The Catechism of the Catholic Church is regarded as a scholarly "textbook," primarily written for educators who will pass on the faith, as the USCCB explains:
The Catechism is intended, first of all, for bishops as teachers of the faith and pastors of the Church. They have the first responsibility in catechesis. Through the bishops, the Catechism is addressed to editors of catechisms, priests, catechists and all others responsible for catechesis. It will also be useful reading for all the faithful.
What's interesting is how an illiterate peasant girl, barely 19 years old, is quoted several times in the Catechism.
She may not have been a scholar of the law, but she certainly was a scholar of the interior life.
Where is St. Joan of Arc quoted?
St. Joan of Arc is quoted a total of four times in the Catechism of the Catholic Church.
The first time she is quoted is in the section on "I believe in God the Father":
It means coming to know God's greatness and majesty: "Behold, God is great, and we know him not." Therefore, we must "serve God first."
She is then quoted in the section, "I believe in Jesus Christ":
The name of Jesus is at the heart of Christian prayer. All liturgical prayers conclude with the words "through our Lord Jesus Christ." The Hail Mary reaches its high point in the words "blessed is the fruit of thy womb, Jesus." The Eastern prayer of the heart, the Jesus Prayer, says: "Lord Jesus Christ, Son of God, have mercy on me, a sinner." Many Christians, such as St. Joan of Arc, have died with the one word "Jesus" on their lips.
Next she is featured in the section on, "I believe in the Holy Spirit," thus showing her complete faith in the Holy Trinity!
Christ and his Church thus together make up the "whole Christ" (Christus totus). The Church is one with Christ. The saints are acutely aware of this unity:
A reply of St. Joan of Arc to her judges sums up the faith of the holy doctors and the good sense of the believer: "About Jesus Christ and the Church, I simply know they're just one thing, and we shouldn't complicate the matter."
The Catechism is clearly highlighting her Trinitarian faith and showing her simple, yet strong beliefs in God.
The last quote is found in the section, "God's Salvation: Law and Grace":
Since it belongs to the supernatural order, grace escapes our experience and cannot be known except by faith. We cannot therefore rely on our feelings or our works to conclude that we are justified and saved. However, according to the Lord's words "Thus you will know them by their fruits" - reflection on God's blessings in our life and in the lives of the saints offers us a guarantee that grace is at work in us and spurs us on to an ever greater faith and an attitude of trustful poverty.
A pleasing illustration of this attitude is found in the reply of St. Joan of Arc to a question posed as a trap by her ecclesiastical judges: "Asked if she knew that she was in God's grace, she replied: 'If I am not, may it please God to put me in it; if I am, may it please God to keep me there.'"
Not every saint is mentioned in the Catechism, so this honor shows us the importance of St. Joan of Arc and the reality that "although you have hidden these things from the wise and the learned you have revealed them to the childlike" (Matthew 11:25).
