Excerpt taken from "These Truths We Hold - The Holy Orthodox Church: Her Life and Teachings". Compiled and Edited by A Monk of St. Tikhon's Monastery. Copyright 1986 by the St. Tikhon's Seminary Press, South Canaan, Pennsylvania 18459.
The Sacraments of the Orthodox Church, like the Church Herself, can be said to possess a double character, for they are at the same time inward and outward, visible and invisible. They combine in themselves both an outward visible sign with an inward spiritual grace. For example, in the Holy Eucharist, we eat the Body and Blood of Christ, although visibly they appear to be bread and wine. Likewise, in Holy Baptism there is an outward washing with water, but simultaneously an inward cleansing of sins. Thus, we often speak of the Sacraments as being mysteries, for, in the sense outlined above, what we see is not what we believe.
In most of the Sacraments, the Holy Church takes things that are material, e.g., bread, wine, water, and oil, and make them vehicles of the Holy Spirit, in imitation of our Lord's Incarnation, when, as the Second Person of the Trinity, He took material flesh and made it a vehicle of the Holy Spirit. We also note here another characteristic of the Sacraments, in that they are personal. That is, the grace of God is given to every Christian individually. Therefore, in most of the Sacraments, the Priest pronounces the Christian name of each person as the Sacrament is administered. Thus, for example, at the Holy Eucharist, when giving Holy Communion, the Priest says, the Servant (or Handmaid) of God [Name] partakes....
Customarily, in the Orthodox Church we speak of Seven Sacraments, although we must note that this was not fixed until about the 17th Century. The Fathers themselves disagreed as to the actual number some said two, some six, some ten, and there were even those who said seven, but differed among themselves as to what constituted that seven. Many other sacramental acts, such as the Blessing of Waters at Theophany, the Monastic Tonsure, the Burial Service, and the Blessing of Any Object, for example, possess the same criteria as the earlier definition of sacrament. In any case, the number seven has no absolute dogmatic significance in our Orthodox theology, but is used only for teaching convenience.
The Sacraments, as they are traditionally numbered, are:
1. Holy Baptism
2. Holy Chrismation
3. The Holy Eucharist
4. Repentance (Penance, Confession)
5. Holy Orders
6. Holy Matrimony
7. The Anointing of the Sick