Sacred mysteries in the context of "Optional memorial"

A sacrament is a Christian rite which is recognized as being particularly important and significant. There are various views on the existence, number and meaning of such rites. Many Christians consider the sacraments to be a visible symbol of the reality of God, as well as a channel for God's grace. Many denominations, including the Catholic, Lutheran, Moravian, Reformed (Continental Reformed, Presbyterian, and Congregationalist traditions), Anglican, Methodist and Baptist, hold to the definition of sacrament formulated by Augustine of Hippo: an outward sign of an inward grace, that has been instituted by Jesus Christ. Sacraments signify God's grace in a way that is outwardly observable to the participant.

The Catholic Church, Hussite Church and the Old Catholic Church recognize seven sacraments: Baptism, Penance (Reconciliation or Confession), Eucharist (or Holy Communion), Confirmation, Marriage (Matrimony), Holy Orders, and Anointing of the Sick (Extreme Unction). The Eastern Churches, such as the Eastern Orthodox Church and Oriental Orthodox Church as well as the Eastern Catholic Churches, recognize these as the seven major sacraments, but also apply the words sacred mysteries corresponding to Greek word, μυστήριον (mysterion), and also to rites that in the Western tradition are called sacramentals and to other realities, such as the Church itself. Many Protestant denominations, such as those within the Reformed tradition, preach just two sacraments instituted by Christ: the Eucharist (or Holy Communion) and Baptism. The Lutheran sacraments include these two, often adding Confession (and Absolution) as a third sacrament. Anglican and Methodist teaching is that "there are two Sacraments ordained of Christ our Lord in the Gospel, that is to say, Baptism and the Supper of the Lord", and that "those five commonly called Sacraments, that is to say, Confirmation, Penance, Orders, Matrimony, and Extreme Unction, are not to be counted for Sacraments of the Gospel."

The sacrament of penance (also commonly called the reconciliation or confession) is one of the seven sacraments of the Catholic Church (known in Eastern Christianity as sacred mysteries). Through this sacrament, the faithful are absolved of sins committed after baptism and reconciled with the Christian community. During reconciliation, mortal sins must be confessed and venial sins may be confessed for devotional reasons. According to the dogma and unchanging practice of the church, only those ordained as priests may grant absolution.

Christian terminology and theological views of marriage vary by time period, by country, and by the different Christian denominations.

Catholic and Eastern Orthodox Christians consider marriage as a holy sacrament or sacred mystery, while Protestants consider marriage to be a sacred institution or "holy ordinance" of God. However, there have been differing attitudes among denominations and individual Christians towards not only the concept of Christian marriage, but also concerning divorce, remarriage, gender roles, family authority (the "headship" of the husband), the legal status of married women, birth control, marriageable age, cousin marriage, marriage of in-laws, interfaith marriage, same-sex marriage, and polygamy, among other topics, so that in the 21st century there cannot be said to be a single, uniform, worldwide view of marriage among all who profess to be Christians.

A mystagogue (from Greek: μυσταγωγός, romanized: mystagōgós, lit. 'person who initiates into mysteries') is a person who initiates others into mystic beliefs, and an educator or person who has knowledge of the sacred mysteries of a belief system. Another word for mystagogue is hierophant.

A hierophant (Ancient Greek: ἱεροφάντης, romanized: hierophántēs) is a person who brings religious congregants into the presence of that which is deemed holy. As such, a hierophant is an interpreter of sacred mysteries and arcane principles.

The word comes from ancient Greece, where it was constructed from the combination of τὰ ἱερά (ta hiera, 'the holy') and φαίνω (phainō, 'to reveal').

The General Roman Calendar (GRC) is the liturgical calendar that indicates the dates of celebrations of saints and mysteries of the Lord (Jesus Christ) in the Roman Rite of the Catholic Church, wherever this liturgical rite is in use. These celebrations are a fixed annual date, or occur on a particular day of the week. Examples are the Feast of the Baptism of the Lord in January and the Feast of Christ the King in November. Other dates relate to the date of Easter. Examples are the celebrations of the Sacred Heart of Jesus and the Immaculate Heart of Mary.

The Paschal mystery is central to Catholic faith and theology relating to the history of salvation. According to the Compendium of the Catechism of the Catholic Church, "The Paschal Mystery of Jesus, which comprises his passion, death, resurrection, and glorification, stands at the center of the Christian faith because God's saving plan was accomplished once for all by the redemptive death of himself as Jesus Christ." The Catechism states that in the liturgy of the Church "it is principally his own Paschal mystery that Christ signifies and makes present."

Catholic, Anglican, Lutheran, and Orthodox Christian churches celebrate this mystery during Holy Week and Easter. It is recalled and celebrated also during every Eucharist, and especially on a Sunday, which according to Catholicism is the Pascha of the week.