This catechism aims to present an organic and synthetic exposition of the essential and fundamental contents of Catholic doctrine, both on faith and morals, in light of the Second Vatican Council and the entirety of the Church's Tradition. Its primary sources are Sacred Scripture, the Holy Fathers, the Liturgy, and the Magisterium of the Church. It is intended to serve as a point of reference for catechisms or compendiums composed in various countries.
John Paul II - Apostolic Constitution Fidei depositum:
"The Catechism of the Catholic Church, which I approved last June 25 and whose publication I order today by virtue of apostolic authority, is the exposition of the Church's faith and Catholic doctrine, attested to and illuminated by Sacred Scripture, Apostolic Tradition, and the Church's Magisterium. I declare it a sure norm for teaching the faith and a valid and legitimate instrument at the service of ecclesial communion. May God grant that it serves for the renewal to which the Holy Spirit constantly calls the Church, the Body of Christ, as it journeys toward the unshadowed light of the Kingdom.
Approving the Catechism of the Catholic Church and publishing it as an instrument of public authority belongs to the ministry that the successor of Peter wishes to offer to the Holy Catholic Church, to all the particular Churches in peace and communion with the Apostolic See: that is, the ministry of sustaining and confirming the faith of all the disciples of the Lord Jesus (cf. Lk 22:32), as well as strengthening the bonds of unity in the same apostolic faith.
I therefore ask the pastors of the Church and the faithful to receive this Catechism in a spirit of communion and to use it constantly in fulfilling their mission of proclaiming the faith and calling others to evangelical life. This Catechism is given to them as a reliable and authentic reference text for teaching Catholic doctrine, and especially for composing local catechisms. It is also offered to all the faithful who wish to deepen their knowledge of the inexhaustible riches of salvation (cf. Jn 8:32). It seeks to support ecumenical efforts inspired by the holy desire for the unity of all Christians, diligently presenting the content and admirable coherence of the Catholic faith. The Catechism of the Catholic Church is finally offered to every person who asks us to give an account of the hope that is in us (cf. 1 Pt 3:15) and who wishes to know what the Catholic Church believes.
This Catechism is not intended to replace local catechisms duly approved by ecclesiastical authorities, diocesan bishops, or episcopal conferences, especially when such catechisms have been approved by the Apostolic See. The Catechism of the Catholic Church aims to encourage and facilitate the drafting of new local catechisms that take into account diverse situations and cultures, always preserving the unity of faith and fidelity to Catholic doctrine."