Someone (not Catholic) said to me recently that the main reason he was not a Catholic is that the Catholic Church forced all kinds of rules on worship and ended up inventing the Mass. He claimed that God wants worship to be free and without rules; just a movement of the Holy Spirit (in case you do not know there are a few protestant denominations that have this a basic belief).
No one doubts that the Christians in the fourth and fifth century believed that there were rules for worship. The debate is whether the early Church believed this. When we look at one of the best sources for early Church opinion, the Scriptures (!), we find that they held a very different opinion (in fact, we could call it "Catholic" -- oh, my golly!).
In the book of Hebrews, chapter nine, we read: "even the first covenant had regulations for worship and an earthly sanctuary". Hmmmmm. Notice that? "Even"? That is a very important word here. When we say "even this..." it means that we are comparing two things, and pointing out that both points of the comparison are the same (in spite of any doubts). Such as: "although people might think differently, even the Pope goes to confession". In other words, we all know that laity go to confession, but (in spite of any doubts you might have) the Pope goes as well.
Thus, take that in context with the quote from Hebrews. When the author says "even the first covenant had regulations for worship and an earthly sanctuary", he is saying, "we all know worship in the New Covenant (i.e. in the Catholic Church of A.D. 65) has "regulations" and an "earthly" building where worship occurs. But, also, (i.e. "even") the Old Covenant did too!
He presumes that worship (i.e. the Mass) had regulations and uses that reality (that all of his readers would have known) to make it clear that the Old Covenant did also. "Regulations" does not refer merely to "be here on time" but to things that we today call "rubrics". Those are the rules and guidelines for how a priest is to say Mass, and what everyone is supposed to do in the Mass. Certainly those rules have grown and adapted over time, but they existed all the way back to the first century (and that, while many of the Apostles were still alive to correct any errors about them).
We have regulations for the Mass. Our forefathers had regulations for the Mass. The first century had regulations for the Mass. That is how God's people have always gone before the Lord: with liturgical rules. God does not want chaos, nor does He want us to "wing it" (in spite of what you might have experienced in some Catholic parishes where the priest thinks he has some kind of divine authority to decide for himself how to do the Mass!). How to approach God is structured with the guidance of the Apostles themselves, as the Holy Ghost gave them inspiration. It was not "made up" or added on later: the worship of God is always according to the expectations of God Himself.