Roman Catholicism and Eastern Orthodoxy are grounded in the same theological tradition. They are similar to each other doctrinally and hold teachings that differ from Mormonism.

God

Both Catholicism and Orthodoxy believe God to be the Creator of the universe, and that God’s being is trinitarian—that the persons of Father, Son, and Holy Spirit exist simultaneously in one divine nature. LDS doctrine is, on the other hand, tritheistic; it is subordinationist. The Son is subordinate to the Father, and the Holy Spirit is “sent forth by the will of the Father through Jesus Christ, his son.” Both Catholic traditions teach that God is a self-revealing mystery whose perfect manifestation is in Jesus Christ, who is present to the world in the Church. Latter-day Saints affirm that Jesus Christ has a separate nature and is a separate entity from the Father, and that as Jesus Christ was and is visible, embodied, and glorified, so is the Father.

Christ

According to Catholic belief, Jesus was born of a virgin, and is the “Incarnate Son of God.” As both God and man, he is the “Savior of the World.” For Latter-day Saints Christ was not, is not now, and never will be united in nature or substance with the Father. His oneness with the Father is spiritual in spirit, purpose, and mind. Jesus, in LDS belief, is the Only Begotten Son of the Father in the flesh. He entered mortality, subject to growth as well as being, and fulfilled the will of the Father as exemplar, savior, and mediator. He was not given all power on earth and in heaven until he received the fulness of the glory of the Father.

Atonement

In both Catholic traditions Christ’s Atonement provides access to salvific grace. Christ’s death-resurrection is the saving event and the cross, the symbol of salvation. For Latter-day Saints the Atonement of Jesus Christ was a descending below all things in order to rise above all. He suffered “according to the flesh” because in no other way could he know the anguish of sin and sinfulness, exemplify redemptive love, and reconcile justice and mercy. The Atonement reunites man with God both through sanctification and resurrection. All that Christ received from the Father may be received by man from the Father through Christ. This transformation is akin to the Eastern Orthodox view of theosis. The goal of discipleship is to become, through Christ, the image and likeness of God.

Authority

Catholics believe that Jesus bestowed his pastoral authority on Peter, who thus became the first “Vicar of Christ” and head of the church, and that this authority to teach and to sanctify has been passed on in unbroken succession in the institution of the Papacy. Eastern Orthodoxy holds that Peter was first among equals, therefore patriarchs have equal authority. They also ascribe a special authority to the first seven ecumenical councils. Latter-day Saints believe that Peter held the keys of apostolic authority, which were also conferred upon the Twelve apostles. Priesthood powers are not indelible but inseparably connected to righteousness. The loss of the full keys of the priesthood was a failure to transmit. Their modern reconferral was under the hands of Peter, James, and John. Every worthy male in the Church is to receive ordination to the priesthood with authority to perform saving ordinances and every father is to function as a patriarch to his own family.

Scripture

For Catholics and Orthodox, the Old and New Testament is the “inexhaustible source of Christian belief.” The Canon is closed. For Latter-day Saints the canon remains open. Scripture is the record of prophetic utterance given under inspiration. There is no final revelation. Revelation in ongoing. Neither written scripture, nor natural theology, supersedes the “living oracles.”

Church

Catholicism and Orthodoxy understand the Church as a “communion of saints.” The Holy Spirit enlivens the Church with grace empowering it to carry on the work of Christ in history. It is a community of salvation where the Gospel is preached and the sacraments received. Latter-day Saints believe that with the restoration of the higher priesthood came three elements lost from the New Testament Church: (1) organizational patterns and their related offices, including a quorum of twelve apostles; (2) the spirit of prophecy, and all the spiritual gifts; and (3) the temple with its essential ordinances and practices. Catholics affirm that grace centers in God’s free gift offered through Christ in the sacraments and is infused to the soul. Baptism is essential for salvation. All sacraments are the necessary means of the grace needed for salvation. Mormon rites or ordinances are processes of spiritual rebirth in which the powers of godliness are manifest. They are received by all and all the ordinances are essential to salvation, from baptism to the higher ordinances of the temple. Their efficacy requires proper forms, ordained priesthood authority, and the faith and repentance of the person. There are degrees of salvation and the fulness of salvation or exaltation requires the fulness of the ordinances.

Eucharist

For both Catholic traditions, the Eucharist is a sacrament in which the true body and blood of Jesus is physically present, that is, the actual saving reality of the Lord. The liturgical act of consecration is a true sacrifice in which, through transubstantiation, the elements of bread and wine become the body and blood of Christ. The Orthodox associates the act of the priest in this liturgy with veneration for icons, which represent their prototype who is Christ. Latter-day Saints understand the sacrament as a remembrance of the body and blood of Christ. Sanctification is from the Spirit and takes place in the recipients who bring a broken heart and contrite spirit to the prayer and the partaking.

Marriage and Family

Although Catholicism and Orthodoxy understand celibacy to be a spiritual ideal, marriage is a grace-giving sacrament that symbolizes the bond between Christ and the Church. Catholics hold that this is a life-long contract and do not permit divorce. Latter-day Saints teach that the eternal glorification of the family, and of the community of families within the Church, is the highest spiritual possibility. As the high priest who officiated in the ancient temple was married; and as the apostles were married, so today marriage is a high ordinance, to which others are preparatory. The nurture and love of the family of man, which is ultimately the family of God, is the proper work and glory of the saintly life. When sealed and sanctified by the authority of the priesthood, the covenants and relationships and duties of parenthood continue into the next world.

While honoring Mary, Latter-day Saints have no equivalent of the doctrines of the immaculate conception, perpetual virginity, and bodily assumption of Mary, nor of the Orthodox veneration of icons. Other LDS teachings differ significantly from traditional Catholic teaching: modification of classical readings of the omnipotence and omnipresence of God; the premortal existence of the spirits of all mankind; the affirmation that spirit is refined matter; the Fall as planned, voluntary, and essential to the growth of the soul amid contrast and opposition; the denial of original sin and of pedobaptism; the inclusive nature of the Abrahamic Covenant; and the replacement of heaven-hell distinction with the teaching of degrees of glory in the resurrection.

Bibliography

Florovsky, Georges. Bible, Church, Tradition: An Eastern Orthodox View. Belmont, Mass., 1972.

McBrien, Richard P. Catholicism, Study Edition. San Francisco, 1981.

McManners, John, ed. The Oxford Illustrated History of Christianity. New York, 1990.

Patrinacos, Rev. Nicon D. A Dictionary of Greek Orthodoxy. Pleasantville, N.Y., 1984.

Rahner, Karl, and Herbert Vorgrimler. Dictionary of Theology. New York, 1981.