Mar Mari

Known as the “Apostle of Babylonia,” Mar Mari was a disciple of Addai, one of the Seventy-Two disciples of Jesus, who had evangelized the city of Edessa. Tradition holds that Mari was commissioned by Addai to go further East, into Babylonia, to spread the Christian Faith. He went, first into the city of Nisibis, where he established both the Gospel and Church institutions. Going further into pagan territories, his simplicity and his power of speech enraptured the local people, who at first even considered him a god. He corrected their errors and taught them the truth of the Messiah. Going thus from city to city, he preached throughout Mesopotamia, eventually reaching the Persian capital, Seleucia-Ctesiphon. There again he preached with the power of the Holy Spirit, despite every obstacle, and built a church on a spot of land called Kokhe, the remains of which can still be seen today. An ancient tradition adds that, in every church he built, he placed images of the Jesus, the Blessed Mother, and many of the saints. The traditional date of his death is July 19th, and he is said to have been buried in one of the churches he built, where his relics were honored for centuries afterward.
 

Excerpt taken from the Quddasha of Addai and Mari

Through the Memorial of your Christ, O Lord, make, in your indescribable mercies, a gracious remembrance for all the upright and just fathers who have pleased you, apostles, prophets, and teachers, the martyrs and confessors, the bishops, priests and deacons, and all the children of the holy catholic Church: those who have been signed with the living sign of holy baptism.

Indeed, our Lord and God, grant us your tranquility and peace all the days of your age, that all the dwellers of the earth may know that you alone are God, the true Father, that you have sent your Son and Beloved, our Lord Jesus Christ, and that he, our Lord and God, taught us all purity and holiness in his life-giving Gospel.
 

(Prayer taken from: The Rite of the Divine Mysteries of the Church of the East of the Chaldeans and Assyrians)