There are very few things that offer true, unbreakable consistency. There are very few things on this earth with true constancy, perhaps only one thing. All of us have the Church and its Mass - the Eucharistic Liturgy. The words have been translated into other languages. The priests have turned around to face another direction. The trappings have changed with the change of the times. Yet, at its heart, we celebrate the same Mass celebrated from the very beginning.
In the "First Apology", written in the mid 100's AD, we find a very familiar Mass:
And on the day called Sunday, all ... gather together to one place, and the memoirs of the apostles or the writings of the prophets are read ... then ... the president verbally instructs, and exhorts to the imitation of these good things. Then we all rise together and pray, ... bread and wine and water are brought, and the president in like manner offers prayers and thanksgivings, ... and the people assent, saying Amen; and there is a distribution to each ... they who are well to do, and willing, give what each thinks fit; and what is collected is deposited with the president, who ... in a word takes care of all who are in need. (St. Justin, ch.67)We celebrate the same Mass in New Jersey as in New Zealand. We celebrate the same Mass in a Roman Catholic church in Ireland whether it is 2009, 1009, or just 39. We are connected to each other across the globe and across time - one universal Church, one Body of Christ, in saecula saeculorum.
St. Justin Martyr. The first apology. New Advent. http://www.newadvent.org/fathers/0126.htm (accessed July 28, 2009).