A normative approach to the Regulative Principle is nothing more than Christianity cloaked in liberalism. There are no borders when it comes to a normative approach. What would you use to restrict any form of worship in light of a normative approach? The treatment is defined along an arbitrary line and left up to the imaginations of men. Following a regulative approach delineates clearly based upon God’s word alone.
First, it tends greatly to establish his authority that we do not follow our own pleasure, but depend entirely on his sovereignty; and, secondly, such is our folly, that when we are left at liberty, all we are able to do is to go astray. And then when once we have turned aside from the right path, there is no end to our wanderings, until we get buried under a multitude of superstitions. Justly, therefore, does the Lord, in order to assert his full right of dominion, strictly enjoin what he wishes us to do, and at once reject all human devices which are at variance with his command. Justly, too, does he, in express terms, define our limits, that we may not, by
fabricating perverse modes of worship, provoke his anger against us. -Calvin, The Necessity of Reforming the Church