We think we know a lot, but what we know is very little.

Elder Thaddeus of Vitovnica

 Catechisms

Catechetical Lectures of Saint Cyril of Jerusalem

The famous Catechetical Lectures of Cyril, archbishop of Jerusalem, are a series of 23 addresses St. Cyril gave in the fourth century to new believers preparing for baptism. The last five lectures, concerning the "mysteries," are addressed to the newly baptized Christians in preparation for their first Holy Communion.

Orthodox Catechism by Greek Orthodox Archdiocese of Canada

The Orthodox Faith by Protopresbyter Thomas Hopko

Orthodox Catechism videos from Holy Nativity Orthodox Church by Fr. Michaell Gillis

Orthodox Catechism by Metropolitan Hilarion of the Moscow Patriarchate

Daily Catechism of the Orthodox Church by St Philaret Metropolitan of Moskow, a series of podcasts

Orthodox Catechism St. Andrew Orthodox Church by Fr. Simon

Catechism - Adult Education Saint Basil the Great Orthodox Mission

Fullness of the faith Catechism Class Saint John the Baptist Greek Orthodox Church

Orthodox Catechism videos St. Jacob Orthodox Church

Orthodox Catechism of the Archdiocese of Thyateira & Great Britain

The Ethos of Orthodox Catechesis: The Mind of the Orthodox Church by V. Rev. Fr. George Morelli, Ph.D.

The Orthodox Catechism - The Holy Trinity Romanian Church

An Orthodox Catechism by Fr Josiah Trenham

Books

Entering the Orthodox Church by Metropolitan of Naftos Hierotheos

The reader can study a general framework of catechetical homilies drawn up by the author, which demonstrates how contemporary Catechism can be applied to those wishing to be baptised. An exposition of the Creed (the Symbol of Faith) is provided. There are lists of questions and answers which refer to the basic central points of Orthodox faith and life, the aim being to consolidate the knowledge imparted to the Catechumens so that the Catechism can be as correct and complete as possible.

Orthodox Faith, Worship, and Life by Heirmonk Gregorios of the Koutloumousiou Monastery Mount Athos

Translated from their 2012 Geek edition which was written to help those who are seeking for a closer understanding of the faith, worship and life of the Orthodox Church. first part on faith includes sections on the Triune God, creation, the divine economy, the Mother of God, the Church and the Kingdom of God; the second part on worship describes the feasts, the church building, the Divine Liturgy and the Holy Mysteries of the Church; and the third part concludes with the Life in Christ: the era of the Old Testament, the era of Grace, prayer, asceticism and monasticism, the virtues, and the deification of man. As with his other books, Elder Gregorios widely uses the actual words of the holy Apostles and the God-bearing Fathers of the Church to substantiate its content and theology.

While extensive it is easy to read.

The Orthodox Church by Metropolitan Kallistos Ware

Since its first publication thirty years ago, Timothy Ware’s book has become established throughout the English-speaking world as the standard introduction to the Orthodox Church. Orthodoxy continues to be a subject of enormous interest among Western Christians, and the author believes that an understanding of its standpoint is necessary before the Roman Catholic and Protestant churches can be reunited. He explains the Orthodox views on such widely ranging matters as ecumenical councils, sacraments, free will, purgatory, the papacy and the relation between the different Orthodox churches.

Orthodox Dogmatic Theology: A Concise Exposition by Protopresbyter Michael Pomazansky

Since its publication in Russian in 1963, it has been used as the main theology textbook at Holy Trinity Orthodox Seminary in Jordanville, New York; and since the publication of the first English edition in 1983, it has come to be regarded throughout the English-speaking world as one of the best introductory books on Orthodox theology. Written clearly, simply and concisely, this modern-day classic is accessible not only to theology students but to the contemporary layman in general. As one deeply rooted in the tradition of the Orthodox Church, Fr. Michael quotes abundantly from the Holy Scriptures and the writings of the Holy Fathers, being concerned to present, not human opinions, but Divine Revelation, which has been handed down to us as the Church s certain, unchanging teaching.

Basic Dogmatic Teaching by Protopresbyter Fr. Anthony Alevizopoulos, Dr. of Theology, Dr, of Philosophy of the Church of Greece

Orthodox Catechism and Workbook - Orthodox Prison Ministries

Adult Catechism Series by Fr. Angelo Maggos

Guidelines for a Prospective Catechumen - Saint Peter and Paul Greek Orthodox Church