Not all kinds of decorations are fitting for divine use in church sanctuaries and buildings and no small amount of writing have been made throughout the centuries on what exactly is acceptable for such church decor. As a brief primer, here is a basic list of notes for church sanctuary decoration.
Living Plants:
Uncut flowers and greenery ought not to be placed on altars. The reason for this is simple; plants especially perennials that are not killed (cut) are not true offerings or sacrifices and therefore not appropriate for the altar of the Lord. Due to the presence of soil in which they grow, the presence of living plants ought to be avoided within the bounds of the sanctuary. Soil is the result of corruption and a source of filth in this way, both symbolically and really, and therefore inappropriate to place within the sanctuary and especially so upon the altar. For as it is written:
"And there shall in no wise enter into it [heaven] any thing that defileth... (Apocalypse 21:27)
This practice has no precedent of acceptance in the history of the Church before the modern era and the practice has been routinely condemned.
Rocks, Sand, and other Ascetic Displays:
For similar reasons of perceived filth, raw mineral displays such as using gravel or loose stones are to be discouraged. Crude jugs also ought to be discouraged as these are not fitting vessels of offering before the Lord. No 'disorderly' and ruinous displays are suitable in this way. There is no rationale to justify such crude arrangements. Except for cases of poverty, only gold and silver vessels are suitable for making offerings to God. In such cases, the next most noble material must be used. Crude materials are always unacceptable. The people's best is always acceptable to God. The odd practice of placing sand within holy water stoups and baptismal fonts in place of water during Lent has never been a tradition of the Church; it is entirely a recent perversion and contrary to Christian instinct concerning penitential seasons. Nonetheless, flowers, even dried ones, are always and expressly prohibited during Lent in the General Instruction of the Roman Missal except for Laetare Sunday, and certain other solemnities. If a more aesthetic tone is desired, it is probably best to just go without for lack of fitting options.
Secular and Unchristianed Symbols:
As the church is a sacred building, set aside for holy rites, no wholly secular items ought to be placed as decorations within its bounds. This might take the form of decor for secular holidays or other generic symbols of no particular religious portent. Likewise, any item or symbol of pagan, heretical, or otherwise unchristianed portent must not be given any place of honor within the church. Although national or ethnic symbols such as a flag might be placed within the church with the motive of dedicating what it symbolizes to God, such symbols ought not be placed for its own sake, and must not be given a place of devotion or great prominence. The practice is generally condemned. Symbols within the church are always used only to manifest spiritual realities.
Statuary:
The tradition of the church concerning statuary has always been that the most fitting materials for statuary within churches are gold, silver, fine hardwood, or stone. In cases of poverty, inferior but acceptable materials have been historically allowed to substitute as needed; for example, brass statuary and candle sticks can be used for wont of gold. Natural materials are always preferred over synthetic ones. In North America and Europe, linden (basswood), although it is technically a softwood, is the premier wood for fine wood carvings for use due to its light, highly-workable texture. In the United States and Canada, the use of plaster statuary is endemic among antiques and although it has been condemned as unideal in the past, it must be tolerated as almost all of the best statuary in the United States is cast from the material. Plaster is condemned due to its common, ignoble, and synthetic nature, as well as its lack of material permanence easily damaged by mechanical and environmental means. Nearly all the statuary restored by the studio is plaster.
References:
- Rationale Divinorum Officiorum, Durandus, 1295 c.
- Instructiones Fabricae et Supellectilis Ecclesiasticae, St. Charles Boromeo, 1577
- Churches, their plan and furnishing, Peter F. Anson, 1948
- General Instruction of the Roman Missal, 2010