"Is not the mass the participation in the sacrifice of Christ as other Catholics here have stated?"
We don't put it that way, mm, though I know the Latins do. Over the centuries, the Latin's understanding of the role of the lower clergy at the Eucharist, and hierarchs, has diverged some from what we believe. For us, the Divine Liturgy is, among other things, a participation in the Mystery of the Incarnation, not simply in the passion and the crucifixion. It is also a communal remembrance of the Incarnation. Here's a link to an article for non-Orthodox which speaks about the Divine Liturgy:
Participation in the Divine Liturgy is a sublime spiritual encounter with the Trinity. The following quote from the report of Prince Vladimir's envoys sent out to find a faith for the people of Kiev, is in part in the piece by Fr. Fitzgerald, but I'm posting it here for those who don't read the article:
"When we journeyed among the Bulgars, we beheld how they worship in their temple, called a mosque, while they stand ungirt. The Bulgarian bows, sits down, looks hither and thither like one possessed, and there is no happiness among them, but instead only sorrow and a dreadful stench. Their religion is not good. Then we went among the Germans, and saw them performing many ceremonies in their temples; but we beheld no glory there. Then we went on to Greece, and the Greeks led us to the edifices where they worship their God, and we knew not whether we were in heaven or on earth. For on earth there is no such splendour or such beauty, and we are at a loss how to describe it. We know only that God dwells there among men, and their service is fairer than the ceremonies of other nations. For we cannot forget that beauty. Every man, after tasting something sweet, is afterward unwilling to accept that which is bitter, and therefore we cannot dwell longer here."
1. The Holy Spirit was present. Palpably. Even over the din of restless children.
2. The people were there for one reason. To worship and take part in the eternal. Not because its just what they do on Sundays, not to be seen, not to take part in a Jesus pep rally and be patted on the back for their piety or their pretty singing. To worship.
3. The people loved each other. And they were genuinely welcoming to new faces.
I hadnt perceived all three simultaneously in either the Southern Baptist church of my youth or the United Methodist church of my adulthood in years. Decades.
Isnt it extraordinary, K? The Liturgical Practices of the Eastern Churches are nearly 2,000 years old but they dont get stale. THEY DONT GET STALE. Protestant churches will change their order of worship multiple times in a year. They have those contemporary services.
The ancient Church is very much alive and well. In spite of the fact that it very generally speaking will not defend itself with swords or guns. Merely by the power of the Spirit and the Righteous Bodiless Powers of Heaven. And it is alive.
The Jews tried to abort it. They failed.
The Romans tried to squash it. They failed.
The Heretics tried to sidetrack it. They failed.
The Muslims tried to intimidate it, contain it, run it off, and kill it. They failed.
The Popes of Rome tried to subjugate it. They failed.
The Bolsheviks tried to purge it. They failed.
The Reformers still hilariously and needlessly try to save it. Gospodi pomiluj. They fail.
There is a reason for that.
We don't make judgements about where the Spirit is not. It goes where it will.
But we do know where to find it. We know where it is.