To answer this question let us consult the Orthodox catechism. The word “catechism” in Greek means “teaching, instruction”. The term “catechism” in church literature refers to a manual containing the main provisions of the Christian faith. One such provision is the doctrine of the Sacraments.
The Orthodox Sacraments are the sacred acts manifested in Orthodox church rites, through which believers receive the invisible Divine grace or the saving power of God.
Archpriest Gennady Nefedov, professor of Moscow Theological Seminary, in his book The Sacraments and Rites of the Orthodox Church writes, “The Kingdom of Heaven becomes closer to man in the Sacraments so much that the supreme measure of sanctification is transmitted to man by its gracious power through visible sacred actions. In every Sacrament, a special gift of divine grace is poured out on man.” Archpriest George Florovsky, an outstanding theologian of the 20th century, noted that the Sacraments make up the Church. Without the Sacraments, there can be no Church.
It should also be noted that the Sacraments have existed in the New Testament Church since its very beginning. They were either directly established by our Lord Jesus Christ Himself or by His closest disciples, the Holy Apostles.
One of the main features of the Sacraments is that the grace of the Holy Spirit mysteriously descends on man, changing him in some fundamental way.
For example, the Sacrament of Baptism cleanses man from his original sin and from sin in general. He is united with God. He gets the opportunity to enter into paradise.
The Sacrament of Chrismation bestows on man the grace of the Holy Spirit, which guides him to the path of spiritual life. It is the dedication of a person to be a temple of God and to commit to the life of an Orthodox Christian.
The Sacrament of Marriage makes man and woman one flesh again by the grace of the Holy Spirit. The grace of God is given to them to sanctify their family union. They gain the blessing of the Lord for the continuation of their family.
Through the Sacrament of Repentance, the Lord forgives man his sins and empowers him to understand God’s will regarding himself.
The Sacrament of the Eucharist connects man as closely as possible to our Lord Jesus Christ. The theosis of man takes place.
The Sacrament of Unction gives grace to a person, which heals him so that he could live and be saved in the Church.
The Sacrament of Priesthood confers God’s spiritual authority and power to administer the Sacraments to certain individuals chosen from among the faithful, to nourish and edify the faithful, and to guide the flock of Christ entrusted to them.
From the above, we see that man acquires a certain heavenly virtue in each Sacrament that helps him on his way to the Kingdom of Heaven. When a Sacrament is performed, the spiritual nature of man changes. He receives special gracious gifts of the Holy Spirit, which make him closer to God.
There are seven Sacraments in the Orthodox Church: Baptism, Chrismation, Penitence, Eucharist, Unction, Marriage, and Priesthood. Symbolically, the number seven in Orthodox theology always refers to the fullness of divine grace.
As for the rites, if the sacraments are the spiritual mysterious component of the Church, connecting man and God, then the rites are an external form of worship and devotion; the sacred act, which is done according to a certain order, i.e., having a certain inner spiritual symbolic content.
Rites are external marks of the Sacraments. That is, they make up the outward, visible side of the Sacraments: laying on hands in the Sacrament of Priesthood, anointing with holy oil mixed with wine in the Sacrament of Unction, etc.; reciting certain prayers.
There are rites that may also not correspond to any of the Sacraments. There are many rites in the Church designed to help an Orthodox Christian in his earthly life and to make it a ladder to heaven – a daily journey to the Heavenly Kingdom. These include various molebens and consecrations (of body and worship crosses, houses, cars, etc.). While the Sacraments remain unchangeable and permanent over time, rites can change. So, for example, a moleben for those who want to make an air travel by plane. Until the 20th century, of course, there was no such rite.
The Lord is often likened in sacred texts to a bird that embraces the world like its nestlings in a nest. Through His Church, God wants to sanctify every moment, every detail of human life and, by transforming it, to lead man to salvation. This is the essence of the Sacraments and rites of the Orthodox Church.
Translated by The Catalogue of Good Deeds
Source: https://pravlife.org/ru/content/tainstva-i-obryady-pravoslavnoy-cerkvi-v-chem-otlichie