"Is it possible to find a single instance in Scripture of accepted worship that was not prescribed by God?"
(Dr. James Begg, "Anarchy In Worship," Lyon & Gemmell, Edinburgh, 1875, available at http://www.swrb.com/catalog/b.htm
"The devil has seldom done a cleverer thing than hinting to the Church that part of their mission is to provide entertainment for the people, with a view to winning them...providing amusement for the people is nowhere spoken of in the Scriptures as a function of the Church...
"The need is biblical doctrine, so understood and felt that it sets men aflame." -- Charles Spurgeon
"When Christian men have got somewhat accustomed to defend one true position, the assault is directed to another, and perhaps from a new quarter...it may safely be affirmed that nothing can be more important than questions connected with the acceptable worship of God. The question of the king of Moab must ever be regarded with deep interest by true Christians, "Wherewithal (with what or how) shall I come before God, and bow myself before the Most High."...For two centuries (this question) has been held to be practically settled in the Presbyterian church. But it is now manifestly raised again from an unexpected quarter, and must be settled anew." (Ibid, p. 4), emphasis added
"The whole counsel of God, concerning all things necessary for his own glory, man's salvation, faith, and life, is either expressly set down in scripture, or by good and necessary consequence may be deduced from scripture: unto which nothing at any time is to be added, whether by new revelations of the Spirit, or traditions of men. Nevertheless, we acknowledge the inward illumination of the Spirit of God to be necessary for the saving understanding of such things as are revealed in the word; and that there are some circumstances concerning the worship of God, and government of the Church, common to human actions and societies, which are to be ordered by the light of nature and Christian prudence, according to the general rules of the word, which are always to be observed." Westminster Confession of Faith I:VI, emphasis added
This has come to be known as the Regulative Principle of Worship (referred to as RPW in the following).
"That principle (RPW - WJM) was substantially this, that for all the constituents of worship, you require the positive sanction of divine authority, either in the shape of direct command, or good and necessary consequence, or approved example; and that you are not at liberty to introduce anything else in connection with the worship of God, unless it comes legitimately under the apostolic heading of 'decency and order.' ("Heart and Voice" [Belfast: Aitchison & Cleeland, late 19th century], p. 4. Available at http://www.swrb.ab.ca/catalog/g.htm )
"There is a strange fallacy which seems to mislead men in forming an estimate of the soundness and importance of this principle. Because this principle has been often brought out in connection with the discussion of matters which, viewed in themselves, are very unimportant, such as rites and ceremonies, vestments and organs, crossings, kneelings, bowings, and other such, some men seem to think that it partakes of the intrinsic littleness of these things, and that the men who defend and try to enforce it, find their most congenial occupation in fighting about these small matters, and exhibit great bigotry and narrow-mindedness in bringing the authority of God and the testimony of Scripture to bear upon such a number of paltry points. Many have been led to entertain such views as these of the English Puritans and of the Scottish Presbyterians, and very much upon the ground of their maintenance of this principle.
"Now, it should be quite sufficient to prevent or neutralize this impression to show, as we think can be done,
"1st, That the principle is taught with sufficient plainness in Scripture, and that, therefore, it ought to be professed and applied to the regulation of ecclesiastical affairs.
"2d, That, viewed in itself, it is large, liberal, and comprehensive, such as seems in no way unbecoming its Divine author, and in no way unsuitable to the dignity of the church as a divine institution, giving to God His rightful place of supremacy, and to the church, as the body of Christ, its rightful position of elevated simplicity and purity.
"3d, That, when contemplated in connection with the ends of the church, it is in full accordance with everything suggested by an enlightened and searching survey of the tendencies of human nature, and the testimony of all past experience.
"And with respect to the connection above referred to, on which the impression we are combatting is chiefly based, it is surely plain that, in so far as it exists de facto, this is owing, not to anything in the tendencies of the principle itself or of its supporters, but to the conduct of the men who, in defiance of this principle, would obtrude human inventions into the government and worship of the church, or who insist upon retaining them permanently after they have once got admittance.
"The principle suggests no rites or ceremonies, no schemes or arrangements; it is purely negative and prohibitionary. Its supporters never devise innovations and press them upon the church. The principle itself precludes this. It is the deniers of this principle, and they alone, who invent and obtrude innovations; and they are responsible for all the mischiefs that ensue from the discussions and contentions to which these things have given rise." (William Cunningham, "The Reformers and the Theology of the Reformation", (Edinburgh, Scotland: Banner of Truth,  1989), p. 35, 36, emphasis added. Available at http://www.swrb.com/catalog/c.htm )
"The reading of the Scriptures with godly fear, the sound preaching, and conscionable hearing of the Word, in obedience unto God, with understanding, faith and reverence, singing of psalms with grace in the heart; as also, the due administration and worthy receiving of the sacraments instituted by Christ, are all parts of the ordinary religious worship of God:beside religious oaths, vows, solemn fastings, and thanksgivings upon special occasions, which are, in their several times and seasons, to be used in an holy and religious manner." (Westminster Confession of Faith XXI:V)
"Anything else or different from this (the itemization of the elements of the worship service found in WCF XXI:V above - WJM), and especially anything borrowed from heathenism or the abolished temple-services - as pretended priests, altars, altar-cloths, incense, symbolical vestments, or instrumental music - are entirely without divine warrant, and therefore unlawful. The same thing may be said of all man-pleasing, sensationalism, solo-singing, with any of the peculiarities of the theatre transferred without divine warrant into the worship of the Christian Church." (Begg, op. cit.)