Every week Wednesdays and Fridays are observed as fast days except during the fifty days (between Easter and Pentecost), and on the days of Christmas and Epiphany, when these feasts fall on these days. The reason why Wednesdays and Friday are fast days is as follows.
After the Lord Jesus Christ had finished the operation of His wisdom upon earth, by His Passion, and His Death, and His Resurrection, He appeared to the Apostles and taught them for 40 days. On the 40th day of His rising, as he had told the Apostles before, He again told them of the descending of the Holy Spirit, He ascended into the heavens, seated upon the wings of the Cherubim, and the Seraphim, and the wings of the winds.
On this day we celebrate the feast of presenting the lord Christ to the temple after 40 days of his glorious birth. saint Mary, his mother, the virgin Mary and the elder Joseph, the just man who was the messenger of this mystery, presented the lord Christ in the temple, to fulfill the Mosaic law with which he, to whom be glory! Had commanded the people of Israel, and to offer up offerings as the law ordered.
In Eritrean Orthodox Tewahdo Church, one of the seven fasting periods is the fast of Nineveh.
Baptism is the sacrament given to all who believe in the Mystery of the Trinity and the Mystery of Incarnation for the remission of sin, to obtain adoption from the Triune God, to inherit the kingdom of God. It is called Mystery, because, when the priest recites the prayer of baptism over the water and blesses it, it changes and becomes the water that flowed from the right side of our Lord Jesus Christ while on the Holy Cross and one can receive the invisible grace of the adopted sonhood of God (Jn.19:34-35).
Mystery of Incarnation means the mystery of the descending of God the Son who is one of the Trinity from heaven and taking up flesh and rational soul from the Holy Virgin Mary to become man. The incarnation of God the Son is primarily necessitated for the salvation of the world. Salvation means the restoration of the world to its direct and unimpeded relation with God. Incarnation is the mystery of God becoming man, and man becoming God. “the Word become flesh and dwelt among us” (Jn. 1:14).
The Eritrean Orthodox tewahdo Church has Five pillars of Mysteries through which it teaches and demonstrates its basic religious belief. They are called Pillars of Mysteries due to the fact that they support and strengthen the faithful in religious teaching as a pillar supports a roof. These mysteries have Biblical foundation (1 Cor. 14:19). Accordingly, the five pillars of mysteries are expressed in the Creed which is the confession of our faith.