It was recently when I was studying Mishneh Torah, Maimonides' legal magnum opus. We started on the chapter about prayers (Tefillah u'Birkat HaKohanim). In it, Maimonides starts off by saying that it's a positive Torah commandment to pray. Then he says that the number of prayers one is to say is not in the Torah, nor is the formula for prayer prescribed. Also, there is no fixed time for prayers. All of these ideas contradict what I know about Jewish prayer. Observant Jews pray three times a day. There are a fixed number of prayers with fixed wording. Maimonides seems to contradict himself later by talking about how prayer became fixed during the time of Ezra the Scribe, and how at least in the Amidah, the text is fixed, although we can add our own prayers during the middle fifteen blessings in the Amidah.
This got me thinking about the structure of prayer. If one contrasts the traditional form of Jewish prayer with many forms of Christian prayer, for instance, one would notice that the Christian version of prayer is much more free-form, and much less structured in comparison. Here are some of my own personal thoughts. I think we are seeing another example of how Maimonides presents two seemingly contrasting, but valid viewpoints. It might seem difficult at first to get past the contradiction, but it's more of a paradox that is saying that "there is a time for fixed prayer, and there is a time for unstructured prayer." Although it might not seem like it at times, there is a place for both within Judaism. Clearly, there is fixed prayer, but there is also unstructured prayer called hitbodedut (התבדדות).
Maimonides seems to be saying that in an ideal world, we can always communicate with G-d in the sense that we always know what to say and how to say it. However, we could be having a bad day or a day that is so exciting that it overwhelms the senses to be able to allow the verbal language for self-expression. Even on a "normal" day, finding adequately expressive words can be challenging. When one cannot find the words to say, there is always a text that one can fall back on to make sure that one can communicate with G-d.
On the other hand, too much rigidity can mean not being able to accurately express to G-d because the words might not convey what is stirring up in the soul. Treating prayer simply as a magic formula can become a mechanical, soulless, rote exercise. Sometimes, prayer needs to be more personalized so you feel invested in it. If not, prayer can get stale, and I can tell you, if you're saying the same Amidah three times a day, 365 days a year in the solar calendar, it can get stale. That can be problematic, especially since the Talmud states that one must direct one's heart to Heaven when praying (Berachot 31a). That is why there needs to be a proper balance between the two concepts, and why Maimonides allows for passages to be added to most blessings within the Amidah, as well as why there is still some structure: because he is recognizing that we both need structure and some free space to express our own individualism.
A follow-up question is how we deal with the Amidah. Both the Conservative and Reform movements have already altered the text of the Amidah. In the early 1990s, the Conservative movement released a responsum on whether it's possible to modify the Amidah, in this case, to include the Matriarchs alongside the Patriarchs. Even as an Orthodox Jew, I find for it to make for interesting reading, at least in part because it helps us answer the question about the extent to which prayer is an extension of ourselves, our desires, or what our souls yearn for (Spoiler: the short version of the Conservative responsum is that as the blessing mentions G-d ineffable name and His Kingship, the blessing is valid). I came across this point a few years back when I was struggling with the Jewish morning blessing of "thanking G-d for not making me a woman." Looking at the Jewish law on the flexibility of prayer, as well as the legal permissibility, I found it possible to modify the prayer somewhere along the lines of thanking G-d for creating me in His Image.
The more legalistic arguments notwithstanding, I feel that there is a non-legal argument to be made. I wouldn't be surprised if there are certain feminists out there who want to add the Matriarchs to "stick it to the man." However, both men and women are created in G-d's Image, so no sense in pitting one against another. If we want to express gratitude for all that the Matriarchs did, then I do not see an issue. Much like the Patriarchs, the Matriarchs made positive contributions to their families and communities. And this doesn't even get into just how non-uniform prayer books were before the invention of the printing press.
It's one thing for Conservative liturgy to change. It's a whole different question of whether Orthodox liturgy will change. Even with a history of liturgy being added or modified, I find the probability dubious mainly because of sociological norms. Regardless of whether Orthodox publishers start adding the Matriarchs into the Amidah or even decide to modify other prayers (e.g., much like when they added in the prayer for the State of Israel), it still brings us back to the tension between fixed and spontaneous prayer. Prayer without structure might leave some thoughts unexpressed or have us confront less thoughts than we would have otherwise. Prayer can be considered incomplete without structure. On the other hand, the high level of rigidity can leave us with a lack of expressiveness that defeats the purpose of prayer. Maimonides teaches us the importance of balance. May we find that sense of balance in all our prayers so that we may become closer to G-d!