Catechism of the Catholic Church

Catechism defined: cat·e·chism Noun
1. A book giving a brief summary of the basic principles of Christianity in question-and-answer form.
2. A manual giving basic instruction in a subject, usually by rote or repetition.
3. A body of fundamental principles or beliefs, especially when accepted uncritically.

Since Catholics often make reference to the Catechism of the Catholic Church (CCC), it is only fitting to explain the CCC and why I hold its contents to be true.
The CCC is best explained in the words of its collaborator given 11 October 1992, "John Paul II, Bishop Servant of the servants of God for everlasting memory". This explanation, referred to as the Apostolic Constitution FIDEI DEPOSITUM on the publication of the Catechism of the Catholic Church prepared following the Second Vatican Ecumenical Council, can be seen in its entirety here.
The following are a few lines from the Fidei Depositum that I feel justify my use of the CCC. Please read it with an open mind in order to understand why Catholics use the CCC as a reference.

Guarding the deposit of faith is the mission which the Lord has entrusted to his Church and which she fulfils in every age. The Second Vatican Ecumenical Council...had as its intention and purpose to highlight the Church's apostolic and pastoral mission, and by making the truth of the Gospel shine forth, to lead all people to seek and receive Christ's love which surpasses all knowledge (cf. Eph 3:19).

The principal task...was to guard and present better the precious deposit of Christian doctrine in order to make it more accessible to the Christian faithful and to all people of good will...to show the strength and beauty of the doctrine of the faith.

With the help of God, the Council Fathers in four years of work were able to produce a considerable collection of doctrinal statements and pastoral norms which were presented to the whole Church.

...on 25 January 1985 I convoked an Extraordinary Assembly of the Synod of Bishops... The purpose of this assembly was to celebrate the graces and spiritual fruits of Vatican II, to study its teaching in greater depth in order the better to adhere to it and to promote knowledge and application of it.

On that occasion the Synod Fathers stated: "Very many have expressed the desire that a catechism or compendium of all Catholic doctrine regarding both faith and morals be composed, that it might be, as it were, a point of reference for the catechisms or compendiums that are prepared in various regions. The presentation of doctrine must be biblical and liturgical. It must be sound doctrine suited to the present life of Christians." After the Synod ended, I made this desire my own, considering it as "fully responding to a real need both of the universal Church and of the particular Churches". ...we thank the Lord wholeheartedly on this day when we can offer the entire Church this reference text entitled The Catechism of the Catholic Church, for a catechesis renewed at the living sources of the faith!

...this catechism will make a very important contribution to that work of renewing the whole life of the Church, as desired and begun by the Second Vatican Council.

The Catechism of the Catholic Church is the result of very extensive collaboration: it was prepared over six years of intense work done in a spirit of complete openness and fervent zeal.

In 1986 I entrusted a commission of 12 Cardinals and Bishops, chaired by Cardinal Joseph Ratzinger, with the task of preparing a draft of the catechism requested by the Synod Fathers. An editorial committee of seven diocesan Bishops, experts in theology and catechesis, assisted the commission in its work.

...It can be said that this catechism is the result of the collaboration of the whole Episcopate of the Catholic Church, who generously accepted my invitation to share responsibility for an enterprise which directly concerns the life of the Church.

...the harmony of so many voices truly expresses what could be called the symphony of faith.

A catechism should faithfully and systematically present the teaching of Sacred Scripture, the living Tradition of the Church and the authentic Magisterium, as well as the spiritual heritage of the Fathers and the Church's saints, to allow for a better knowledge of the Christian mystery and for enlivening the faith of the People of God. It should take into account the doctrinal statements which down the centuries the Holy Spirit has intimated to his Church. It should also help illumine with the light of faith the new situations and problems which had not yet emerged in the past.

The catechism will thus contain the new and the old (cf. Mt 13:52), because the faith is always the same yet the source of ever new light.

In reading the Catechism of the Catholic Church we can perceive the wondrous unity of the mystery of God,his saving will, as well as the central place of Jesus Christ, the only-begotten Son of God, sent by the Father, made man in the womb of the Blessed Virgin Mary by sacraments: he is the source of our faith, the model of Christian conduct and the Teacher of our prayer.

The Catechism of the Catholic Church, which I approved 25 June last and the publication of which I today order by virtue of my Apostolic Authority, is a statement of the Church's faith and of Catholic doctrine, attested to or illumined by Sacred Scripture, Apostolic Tradition and the Church's Magisterium.

For more information on the CCC, please refer to the CCC paragraphs 4-25.

I hope this has enlightened someone.