The liturgy of “the early church” actually begins in the fourth century.

http://calvinistinternational.com/2014/02/24/quest-historic-liturgy/

...what many people typically mean when they speak of the liturgy of “the early church” is actually a historically-contingent sample from a span of about four or five hundred years, beginning with, rather than climaxing in, the fourth century. This sort of observation does not tell us whether a certain liturgical form is good or bad, nor even better or worse, but what it does do is place the entire discussion firmly in the realm of human law, tentative investigation, and, thus eventually, prudential application.

What this means for Protestants seeking to appropriate the findings of the liturgical renewal movement is that they must always receive such proposals in a somewhat critical manner. They can be appreciative of good order, appealing aesthetics, and even a sort of historical pedigree, but they can never confuse these things with divine right, nor even “the catholic tradition.” All “historic” liturgies should be brought into conversation with biblical and Reformational principles. Perhaps, most of all, we should keep in mind the great freedom we have in these manners. A certain amount of diversity is granted to us by the freedom of the gospel, and this diversity has been with the Christian church since the earliest days.