There is a light bulb joke the asks “How many Orthodox monks does it take change a light-bulb?” The response is “Change??”
There is a sense among Orthodox (Catholic) Christians that there is no change in orthodoxy but what does this mean? Is there absolutely no-change in any aspect of orthodoxy? We may also ask what to we mean by orthodoxy? Is it a description of creed/dogma and practice or only creed/dogma or only practice? Then with any one of these options there is the question of what creed/dogma and what practice and the extent of creed/dogma or practice.
As a general rule, to be an Orthodox (Catholic) Christian is to be someone who accepts the Tradition, or traditions, of the Church that we established by Christ through the Apostles (i.e. Apostolic) and maintained by the Fathers (the succession of Bishops). (In practice many are often Orthodox Christians because they were baptised by Orthodox priests as infants and not due to an active choice of accepting Orthodox Tradition.) If this is a suitable definition of being Orthodox as opposed to being Protestant or Roman Catholic then the Tradition or traditions that are accepted as being Apostolic must be the same as those established through the Apostles which means that this Tradition or traditions cannot change otherwise have would cease to be the same as the Tradition or traditions of the Apostles. Does this mean though that there is absolutely no change in faith and/or practice?
Roman Catholics in general accept a development of doctrine even while accepting the principle of Tradition by the reasoning that any development of doctrine must be consistent with or implicit in Apostolic doctrine and thus not a change in Apostolic doctrine. To some level this is also accepted by Orthodox Christians with the real issue being the consistency of any ‘developed doctrine’ with Apostolic doctrine. All this reinforces the principle of no change.
Recently, in a conversation, it was mentioned that no change only applies to dogma or doctrine. What does this mean? Is this to divide faith/creed and practice? If so then how does one draw the line between them? It would seem that it should be easy to distinguish between faith/creed and practice. Faith/creed is what one accepts in a mental manner and practice is what one does according to this mental faith/creed. While this is true, to divide the two is another matter because the two are linked: we do a certain practice because we have a certain faith/creed or a certain practice is inconsistent with a certain faith/creed. If they are so linked then a change of practice will have implications to the faith/creed and would imply a certain change of faith/creed. However, there may be multiple consistent practices with a particular faith/creed and a particular practice may be connected to multiple aspects of faith and creed. This can allow for diversity without change or difference and that any particular practice may not necessarily need to be unchanging, although there may be many that are unchanging. Also there can be different faith/credal reasons for a particular practice and also the possibility to have a varied understanding of an issue of faith without that causing a change in practice. Hence, given some room for diversity, it would not be correct to say that only doctrine/dogma is unchanging because it is linked with practice and such links may mean that a particular practice also cannot change.
This latter is borne out in the witness of the Fathers, especially when we consider the Ecumenical Councils. These have always, albeit in two cases in a delayed manner, consisted of two aspects: a definition of faith; and a collection of Canons to guide practice. This demonstrates the link between faith and practice. The greatest part of the reason for the Schism between Old and New Romes was over issues of practice and the ‘faith’ issue surrounding the filioque was one of the matters but not in itself on another/higher level of cause of Schism. It is only in recent times with a move to saying that only doctrine cannot change that one reduces the cause of the Schism to the ‘filioque’ or other dogma.
An example of where it is impossible to draw a line between faith and practice. Baptism is an action (practice) yet it is included within the Creed as an element of faith. It is not a doctrine regarding the Trinity but a practice that unites one to the Trinity in Christ. We say that it is a practice and not doctrine/dogma therefore can be changed/removed. Yet it is in the Creed so it is an element of dogma/doctrine and cannot be changed. This shows the inconsistency between the evidence of Orthodox Tradition and proposal that only dogma/doctrine cannot change. Other practices, such as the use of chrism after baptism, the use of wine and water during the Eucharist, ordaining clergy by laying on of hands are not open to change yet they are not written into the Creed as dogma.
There is evidence of change and diversity in the Fathers. An explanation for diversity and some change has already been given above. Another explanation is the freedom that the hierarchy have to rule; that is they are not mere robots but share in genuine authority to rule the Church with Christ. Thus, each local church, region of churches, and Patriarchate are free to exercise their own practices and have their own customs some differing from the freedom of the Apostles. Nevertheless, they are obliged to maintain the practices confirmed as universal by the Ecumenical Councils and recognised local councils should not be changed by a local/regional/patriarchal/ecumenical council, although they can be qualified if necessary because practice should always be framed by what is physically possible. This also applies to other well recorded Apostolic Traditions. It is not only doctrine/dogma that is non-changing but also practices as established by the Fathers to have universal application. There may be debate about what practices are to be universal and unchanging but there are such universal practices as also there are practices that are not fixed. This can also apply to dogma/doctrine, although this is less flexible because it has a priority over practice and is easier for universal consistency. Variation and change in doctrine/dogma that has not been universally established, and is consistent with that which is, is possible within Orthodoxy.
So, in an answer to the questions, there is no change in both matters of faith/creed and of practice that are established as Apostolic and are confirmed by the Fathers, particularly in Ecumenical councils. However, change and diversity is freely permitted on other matters.
Due to the length of the post some things have been assumed and not developed in full of please comment or criticise as you think constructive.