Epistle for the Sunday of the Myrrh-Bearing Women (Acts 6: 1-7 with footnotes):
[1] And in those days, the number of the disciples increasing, there arose a murmuring of the Greeks against the Hebrews, for that their widows were neglected in the daily ministration. [2] Then the twelve calling together the multitude of the disciples, said: It is not reason that we should leave the word of God, and serve tables. [3] Wherefore, brethren, look ye out among you seven men of good reputation, full of the Holy Ghost and wisdom, whom we may appoint over this business. [4] But we will give ourselves continually to prayer, and to the ministry of the word. And they chose Stephen, a man full of faith, and of the Holy Ghost, and Philip, and Prochorus, and Nicanor, and Timon, and Parmenas, and Nicolas, a proselyte of Antioch.
[1] “Greeks”: So they called the Jews that were born and brought up in Greece.
[6] These they set before the apostles; and they praying, imposed hands upon them. [7] And the word of the Lord increased; and the number of the disciples was multiplied in Jerusalem exceedingly: a great multitude also of the priests obeyed the faith.
IOW, deacons are ordained to help bishops with the material needs of the Church.
However, in the Eastern Catholic Churches the deacon assists the priest in offering the Liturgy. In fact, the rubrics for the Liturgy assume that a deacon will be assisting the priest. Since most parishes don’t have a deacon, the priest assumes the duties of the deacon as well as the priest as the old axiom goes: “A higher Order may assume the functions of a lower Order but a lower Order may not assume the functions of a higher Order.”
Example: The petitions of the ektenias (litanies) are supposed to be chanted by the deacon, not the priest. Yet the priest must chant them in the absence of a deacon. However, a deacon cannot assume the duties of a priest (e.g. he cannot say the words of consecration).
Does that help? Maybe one of the priests can “fact-check” my information.