Second Vatican Council in the context of "Eastern Catholic liturgy"

The Roman Rite (Latin: Rītus Rōmānus) is the most common ritual family for performing the ecclesiastical services of the Latin Church, the largest of the sui iuris particular churches that comprise the Catholic Church. The Roman Rite governs rites such as the Roman Mass and the Liturgy of the Hours as well as the manner in which sacraments and blessings are performed.

The Roman Rite developed in the Latin language in the city of Rome and, while distinct Latin liturgical rites such as the Ambrosian Rite remain, the Roman Rite has gradually been adopted almost everywhere in the Latin Church. In medieval times there were numerous local variants, even if all of them did not amount to distinct rites, yet uniformity increased as a result of the invention of printing and in obedience to the decrees of the Council of Trent of 1545–1563 (see Quo primum). Several Latin liturgical rites which had survived into the 20th century were abandoned after the Second Vatican Council. The Roman Rite is now the most widespread liturgical rite not only in the Catholic Church but in Christianity as a whole.

Latin liturgical rites, or Western liturgical rites, is a large family of liturgical rites and uses of public worship employed by the Latin Church, the largest particular church sui iuris of the Catholic Church, that originated in Europe where the Latin language once dominated and further by Western Rite Orthodoxy and Independent and Old Catholicism. Its language is now known as Ecclesiastical Latin. The most used rite is the Roman Rite.

The Latin rites were for many centuries no less numerous than the modern Eastern Catholic liturgical rites. The number of Latin rites and uses is now much reduced. In the aftermath of the Council of Trent, in 1568 and 1570 Pope Pius V suppressed the breviaries and missals that could not be shown to have an antiquity of at least two centuries in favor of the Roman Missal and Roman Breviary. Many local rites that remained legitimate even after this decree were abandoned voluntarily, especially in the 19th century, in favor of the Tridentine Mass and other Roman Rite rituals. In the second half of the 20th century, most of the religious orders that had a distinct liturgical rite chose to adopt in its place the Roman Rite as revised in accordance with the decrees of the Second Vatican Council (see Mass of Paul VI). A few such liturgical rites persist today for the celebration of Mass, since 1965–1970 in revised forms, but the distinct liturgical rites for celebrating the other sacraments have been almost completely abandoned.

In the Catholic Church, an association of the Christian faithful or simply association of the faithful (Latin: consociationes christifidelium), sometimes called a public association of the faithful, is a group of baptized persons, clerics or laity or both together, who, according to the 1983 Code of Canon Law, jointly foster a more perfect life or promote public worship or Christian teaching, or who devote themselves to other works of the apostolate.

A 20th-century resurgence of interest in lay societies culminated in the Second Vatican Council, but lay ecclesial societies have long existed in forms such as sodalities (defined in the 1917 Code of Canon Law as associations of the faithful constituted as an organic body), confraternities (similarly defined as sodalities established for the promotion of public worship), medieval communes, and guilds.

Catholic spirituality includes the various ways in which Catholics live out their Baptismal promise through prayer and action. The primary prayer of all Catholics is the Eucharistic liturgy in which they celebrate and share their faith together, in accord with Jesus' instruction: "Do this in memory of me." The Catholic bishops at the Second Vatican Council decreed that "devotions should be so drawn up that they harmonize with the liturgical seasons, accord with the sacred liturgy, are in some fashion derived from it, and lead the people to it, since, in fact, the liturgy by its very nature far surpasses any of them." In accord with this, many additional forms of prayer have developed over the centuries as means of animating one's personal Christian life, at times in gatherings with others. Each of the religious orders and congregations of the Catholic church, as well as lay groupings, has specifics to its own spirituality – its way of approaching God in prayer to foster its way of living out the Gospel.

Pope Paul VI (born Giovanni Battista Enrico Antonio Maria Montini; 26 September 1897 – 6 August 1978) was head of the Catholic Church and sovereign of the Vatican City State from 21 June 1963 until his death on 6 August 1978. Succeeding John XXIII, he continued the Second Vatican Council, which he closed in 1965, implementing its numerous reforms. He fostered improved ecumenical relations with Eastern Orthodox and Protestant churches, which resulted in many historic meetings and agreements. In January 1964, he flew to Jordan, the first time a reigning pontiff had left Italy in more than a century.

Montini served in the Holy See's Secretariat of State from 1922 to 1954, and along with Domenico Tardini was considered the closest and most influential advisor of Pope Pius XII. In 1954, Pius named Montini Archbishop of Milan, the largest Italian diocese. Montini later became the Secretary of the Italian Bishops' Conference. John XXIII elevated Montini to the College of Cardinals in 1958, and after his death, Montini was, with little to no opposition, elected his successor, taking the name Paul VI.

Catholic ecclesiology is the theological study of the Catholic Church, its nature, organization and its "distinctive place in the economy of salvation through Christ". Such study shows a progressive development over time being further described in revelation or in philosophy. Here the focus is on the time leading into and since the Second Vatican Council (1962–1965).

Pope Paul VI stressed the importance of the church's self-knowledge in his first encyclical letter, Ecclesiam Suam:

Order of Mass is an outline of a Mass celebration, describing how and in what order liturgical texts and rituals are employed to constitute a Mass.

The expression Order of Mass is particularly tied to the Roman Rite where the sections under that title in the Roman Missal also contain a set of liturgical texts that recur in most or in all Eucharistic liturgies (the so-called invariable texts, or ordinary of the Mass), while the rubrics indicate the rituals, and the insertion points of the variable texts known as the proper of the Mass. Having been virtually unchanged for many centuries, the Roman Catholic Order of Mass changed decisively after the Second Vatican Council.

The Catholic Church and Eastern Orthodox Church broke communion during the East–West Schism of 1054. While an informal divide between the East and West existed prior to the split, these were internal disputes, under the umbrella of the recognised “one, holy, catholic and apostolic Church” of the Nicene Creed. It is only after the formal schism of the 11th century that two, distinct churches are seen to exist, and thus commence relations. The split has, on both sides, been immensely lamented, for it defeats the exhortation of Jesus Christ “that they may all be one" (John 17:21). The anguish over the past has spurred both sides, particularly in recent decades, to work towards restoring Christian unity through ecumenical efforts.

Relations between the East and West have warmed over the last century, as both churches embrace a dialogue of charity. The Second Vatican Council (1962–1965) ushered in a new era of relations for the Roman Church towards the Orthodox Church, fondly describing the Orthodox as “separated brethren” with valid sacraments and an apostolic priesthood. The Orthodox Church, on the other hand, encouraged local churches to prepare for future dialogue in the Third Pan-Orthodox Conference in Rhodes (1964), and has since engaged in several ecumenical efforts with the Vatican. Significantly, in 1965 Pope Paul VI and Ecumenical Patriarch Athenagoras I of Constantinople jointly lifted the mutual excommunications of 1054. More recently, in November 2019, the current Patriarch of Constantinople, Patriarch Bartholomew, has stated he believes Orthodox re-union with the Catholic Church is inevitable.

The Catechism of the Catholic Church (Latin: Catechismus Catholicae Ecclesiae; commonly called the Catechism or the CCC) is a reference work that summarizes the Catholic Church's doctrine. It was promulgated by Pope John Paul II in 1992 as a reference for the development of local catechisms, directed primarily to those (in the church) responsible for catechesis and offered as "useful reading for all other Christian faithful". It has been translated into and published in more than twenty languages worldwide.

John Paul II referred to it as "the Catechism of the Second Vatican Council", and Pope Benedict XVI described it as "one of the most important fruits of the Second Vatican Council".