Recently I have been involved in several discussions and study sessions on liturgy in our church. One question which arises for some (though it should arise for all) is "What are the 'authorised' services of our church?" Another question is 'Why are there so many rules about liturgy?'
The first question is tackled in a paper I provide below, a paper first delivered to our Post Ordination Training group, tweaked for an archdeaconry meeting soon after, and touched up a little for presentation below.
The second question requires care. Liturgy is a technical subject in the sense that a service can be analysed into many parts, each part discussed in terms of the tradition lying behind it and the theology it seeks to give expression, with each and every such discussion invoking many terms, including references to items of vesture, some of which are known only to advanced liturgists or people with Wikipedia at their finger tips (try: anaphora, epiclesis, extraordinary form, ad orientem, melismata, wimple, burse). That there might be rules, formal and informal which govern what we do (and prohibit what we should not do) is no surprise, but the sheer number can overwhelm the person new to following the rules (say, a deacon or a priest or other licensed liturgical leader).
In my view we should step back from the minutiae of rules and ask what the purpose of any and every liturgical rule is. I suggest the purpose is simply this: to safeguard the gospel.
The gospel of Christ inspires our offering of thanksgiving to God. What we say in liturgy expresses what we believe the gospel announces, that Christ has saved us. If we do liturgy badly then we may distort the gospel. When we do liturgy well we proclaim the gospel in its fullness.
Now to the paper ...
I recommend reading the above in conjunction with a recent post by Bosco Peters on Authorised Worship.