The Biblical Basis of Man-Made Liturgy
Is a Christian free to worship God however he pleases? I think all of us would intuitively answer “No” to that question. Man’s duty to worship God is too important to just be a free-for-all. This is especially true for Christians who have God’s Revelation, particularly the Bible. The Confessional Reformed tradition (rightly) understands that man is not only not free to worship however he pleases (since this would ultimately tend towards man worshipping himself), but in fact man should not worship in any way not clearly laid out in God’s Word. This notion is known in the Reformed tradition as the “Regulative Principle of Worship” (RPW), wherein man must worship God how God has revealed He wants to be worshiped. The goal of this post is to show that while the RPW sounds good on the surface, I think it quickly runs into some serious problems.
Most non-Reformed Protestant traditions (especially Evangelicalism) take a more ‘lax’ approach to Christian worship, generally holding to the idea that many forms of worship are acceptable so long as they don’t contradict Scripture. That view doesn’t see the Bible as prescribing a specific form of worship, but rather only ‘ruling out’ unacceptable practices (e.g. the use of images). Clearly, the ‘worship question’ is not trivial, yet Sola Scriptura has led to a more relativistic, human-centered approach to Christian worship, as each believer is seen as autonomous, not having to be subject to any specific pastor/congregation and having the ‘right’ to worship however he pleases (including simply sleeping in on Sunday). Rather than go on a tangent about Sola Scriptura in general though, I think the Confessional Reformed RPW view should be analyzed in light of what Scripture says, because it seems to me the RPW has little to no Scriptural support – which is quite ironic.
The most obvious starting point in discerning whether the RPW is actually Biblical is to find whether Scripture lays out any specific example of Christian liturgy. Some Evangelicals will say they base their Christian liturgy off of “The Acts 2 Church,” but at that point in the Church (Acts 2:42-47) there wasn’t even a book of the New Testament written yet, so “The Acts 2 Church” couldn’t even have been a Sola Scriptura based Christian liturgy. Moreover, there aren’t really any details here or anywhere else in Scripture of what precisely early Christian liturgy looked like. (Such information comes mostly from inspired Apostolic oral teaching, which Protestants reject.) So given this lack of specific Biblical testimony, from what I’ve been able to gather, the RPW is really a bunch of verses strung together to ‘form a principle’ (hence the name RPW), which ironically leads Reformed liturgy becoming more a work of men than a command of God.
To see this problem more clearly, consider John Calvin’s official liturgy which he instituted in Geneva in 1542 : The liturgy begins with Confessing Sins, Prayer for Pardon , then goes on to Scripture Readings , a Sermon, a Collection of Alms, the Lord’s Prayer, the Apostles’ Creed, Words of Institution, Consecration of the Bread and Wine, and concludes with the Aaronic Blessing (Num 6:22-27). Now we can all agree that none of this is necessarily a bad thing when considered individually. The problem is that this “liturgy” is nowhere instituted in the Bible. Is man really free to just lift the Aaronic Blessing from the OT and append it to the Christian Liturgy and call this approved by God? Not if they are being honest. And as anyone can see, a whole host of liturgies can be invented using this cut-and-paste method.  This is clearly an unacceptable position for a Christian to take.
Given this brief look at Reformed Liturgy, it seems to me that the RPW not only is self-refuting (since it’s not a specific principle taught in Scripture, just a gathering of verses here and there), it also exposes one more flaw in Sola Scriptura, since it makes liturgy more or less relative to the whims of the individual (guided at most by some generic ‘principles’). So while it is good that the Reformed take worship of God seriously, they unfortunately find themselves in a conundrum wherein as hard as they try to “worship God as He has commanded in His Word,” they end up worshiping God according to blatant traditions of men. Only an appeal to inspired Apostolic oral teaching and Apostolic Succession (both of which Catholicism has) can ground a Christian in true worship and prevent a slide into man-centered relativistic “worship”.
 It’s not clear to me how the Confession of Sins and Prayer for Pardon is compatible with the Reformed idea that man’s sins are completely forgiven at the moment of Justification and that God only views man in light of the Righteousness of Christ imputed to him. Why ask for forgiveness of sins every Sunday if you believe all your sins were already forgiven and that God never counts your sins against you?
 It’s also not clear to me if the Scripture reading is taken from a fixed lectionary of readings (if so, where did the Bible teach this?), or if the Scripture reading is a randomly chosen text (and if so, where does the Bible say we worship God by randomly selecting which texts we feel like reading?).
 Note that in the Wiki link above, Calvin had noticeably modified this 1542 liturgy from his 1540 liturgy, including removing Psalm 124:8 from the start, removing the recitation of the Ten Commandments (with each Commandment followed by Kyrie Eleison) and removing the Nunc Dimittis before the conclusion. Did the Bible tell him he could make such revisions? Does he not realize a whole host of liturgies can come about by this mixing/cutting/pasting?