Let me talk about the aspect of liturgy getting into me (and you too, when you experience it!):
The use of the same prayers is important because you learn them by heart. It is important that we learn them by heart because they connect us to one another and also to all who have come before us in the Church. In fact, many of them that are used in the traditional liturgy (like that of the Book of Common Prayer) date back to the first 500 years of the church.
Another reason that it is important to experience these prayers and let them get "into you" is that they are filled with Scripture. I think that one reason they can be so highly scriptural is that they are not "off the cuff" prayers. The original writers took time to encapsulate what they intended to say and to lean on the idea of responding to God with much of his own word to him.
Because they have been thought about and written down, they are direct and to the point. They get to the heart of what is being asked for. Many of them are called collects because they sum up and "collect" one's thoughts around a particular theme. For example, the Collect of Purity:
Almighty God, unto whom all hearts are open, all desires known, and from whom no secrets are hid. Cleanse the thoughts of our hearts by the inspiration of your Holy Spirit, that we might perfectly love you and worthily glorify your holy name, through Christ our Lord. AmenThis prayer pounds a whole lot of biblical truth into a few sentences. It gives us a particular description of God focusing on his omniscience and also his omnipresence. It points us to the working of the Holy Spirit through whom we depend on our union with Christ and who works in the cleansing that comes through the forgiveness of Christ. It also includes the purpose for our petition to God: that we might love him and glorify him (in the context of the Eucharist, through our worship of him and response to his gifts of Christ's body and blood). This prayer is given to the Father through Jesus, which is what Christ meant when he said for us to pray in his name. This prayer packs a lot of theology into it and we are able to be edified and reflect on that theology because we have the prayer in front of us and we can pray it along with the priest and in full agreement with him.
One last thing about the importance of liturgical prayers: They are habitual. They are at the hear of Anglicanism's prayer book: The Book of Common Prayer. It is common, not because it is lowly or vulgar, but because it is used by all! All people truly share in the prayer because all are to be praying the same prayer together. All the prayers in the prayer book are common to all of the people who worship using those prayers. There is agreement in prayer that is not as possible when people are just praying spontaneously all the time.
With a "spontaneous" prayer that is unknown to the people, you never know where the person is going or what they might say, whether it will necessarily be orthodox or not. This limits the amount of agreement, I believe, because we focus on the meaning of the words instead of actually praying with the person. That may seem strange, but it isn't. Think about it like this: If you are having to focus on every meaning of every word in a conversation, are you really involved in being in the moment of conversation with that person? Is it not easier when the meaning of the words are already known to be able to be in the moment with someone?
I may have more to say on this, but I do want to continue more with the importance of the liturgy in regard to dealing with theology and its practicalness in my next post.
Picture courtesy of: http://www.wabashakelloggparishes.org/sacraments.html