From Calvin's Institutes, IV,X,32. Interesting point he makes. As Reformed people we are big on: "Don't change it (ceremonies, etc.) if there is no reason to." Calvin says that we do well to make changes once in awhile to the external ceremonies so that we stay beyond the externals and continue, or again appreciate, the substance. Calvin:
32. Observances should be few and edifying
Moreover, we must use the utmost diligence to prevent any error from creeping in which may either taint or sully this pure use. In this we shall succeed, if whatever observances we use are manifestly useful, and very few in number; especially if to this is added the teaching of a faithful pastor, which may prevent access to erroneous opinions. The effect of this procedure is, that in all these matters each retains his freedom, and yet at the same time voluntarily subjects it to a kind of necessity, in so far as the decency of which we have spoken or charity demands. Next, that in the observance of these things we may not fall into any superstition, nor rigidly require too much from others, let us not imagine that the worship of God is improved by a multitude of ceremonies: let not church despise church because of a difference in external discipline. Lastly, instead of here laying down any perpetual law for ourselves, let us refer the whole end and use of observances to the edification of the Church, at whose request let us without offence allow not only something to be changed, but even observances which were formerly in use to be inverted. For the present age is a proof that the nature of times allows that certain rites, not otherwise impious or unbecoming, may be abrogated according to circumstances. Such was the ignorance and blindness of former times, with such erroneous ideas and pertinacious zeal did churches formerly cling to ceremonies, that they can scarcely be purified from monstrous superstitions without the removal of many ceremonies which were formerly established, not without cause, and which in themselves are not chargeable with any impiety.