Readings from Scripture have been an essential part of church worship since the first century. In the early Church, the readings and even the canon of books from which they were selected were chosen by the bishop, the primate of the local Church.

The tradition of dividing the biblical text into a cycle of excerpts for worship has its roots in the 3rd century and took final shape in the 5th and 6th centuries. The present-day cycle of Scripture readings in the Orthodox Church assigns a so-called ordinary reading for each day of the liturgical year.

This cycle begins at the Easter vigil with the first passages from the Gospel of John and the Acts of the Apostles, and continues until the next Easter. Thus the whole New Testament, except the Book of Revelation, is read in one year. On feast days, special passages are selected either because they describe the celebrated event or because they are connected with the feast in some other way. The ordinary readings for that day can either be omitted or read together with the feast-day readings at the Divine Liturgy.

In addition, certain Gospel excerpts are read during matins and vespers.

The Orthodox reading cycle consists mainly of the ordinary readings for each day.