The use of projection screens in place of printed books or bulletins in the Divine Service has become quite prevalent in some parts of North American Lutheranism. With this said, I am not aware of any major study that has reviewed the implications of using said devices within the liturgical context, let alone for catechetical functions outside the sanctuary. Obviously there is nothing in the Bible that forbids them as they didn't exist until recently. But this does not thereby commend their use to us. Even when things are neither commanded nor forbidden, this does not mean they are completely indifferent or that they may be used willy-nilly. What follows below are a few reflections and cautions regarding the use of projection screens (PowerPoint, etc) in the sanctuary or for the Divine Service in general. I certainly do not expect these reflections to be definitive, but as grist for conversation and hopefully to give pause over jumping both feet in into this novelty.
1. Regarding the transient and ethereal nature of the projection.
Obviously the computer, projector, and monitor can be switched on and switched off. During the progression of a service various lyrics, pictures, and information can be flashed onto the screen for varying lengths of time. This means that reading ahead in the service is not a possibility for the worshiper and neither for the liturgist, without a hand-held version of the service. This also means that for the parishioner who is concerned to be a Berean Christian (Acts 17:11) about the content of the service, they have no means to evaluate such prior-to or during the service until it comes into being on the screen(s). A thing that can lose power cannot be accounted for and is easily forgotten. Yet the effect of these things upon the heart and mind, and the soul can be lasting, even negatively with harm. There is no test of time, no evaluation of the church catholic, no ecclesial awareness at all in what is produced from an individual or committee in one locale. It then becomes liturgical Russian-roulette. Furthermore, even when said content is good, meditation on the text or other item projected is also a fleeting moment. (And what trouble there is in a power outage!) What is given in this context is a brief appearance, reflecting what someone thought at a moment. It is to engender an experiential response to know the spiritual realm and in that has some affinity with Gnosticizing tendencies of centuries past.
2. Regarding the dangerous potential of weekly chosen content.
Anytime one changes format or mode of presentation, the casting aside of standardized content becomes a real possibility and even likely. For Lutherans who subscribe to Augsburg Confession and Apology XXIV, this is not something that should be ignored or taken for granted. Even before the advent of projection screens in Lutheran sanctuaries, we have seen wholesale rejection of the liturgical heritage of our Confessions. The liturgy du jour produced by pastor, worship committee, praise team, or what have you becomes the standard content of the screen. And the liturgy du jour is hardly built around a format that is Divine Service (Acts 1:1-2; Luke 22:27; Revelation 3:20; Romans 10:17), or leitourgia in the sense of Apology of the Augsburg Confession XXIV.78-83. This article of the Confessions still stands even when Formula X is invoked by the practitioners of liturgy du jour. While, in the LCMS, we do have resources like Lutheran Service Builder, this still does not preclude liturgical tinkering, or worse, liturgical borrowing from the Arminians, Wesleyans, and charismatics. Formula X, on adiaphora, never condones importing heterodoxy-laden songs and practices and rites from the schwärmer. On the contrary it assumes that adiaphora are used to avoid confessional ambiguity in a liturgical context. In this area, novel use of said technology in the worship context may lend itself well to promoting an Arminian to charismatic understanding. Certainly we have a history among us of importing practices that originated among non-Lutheran protestants without much prior theological reflection out of undisciplined zeal, curiosity, items being offered in a supply catalog, or even coveting. This is worse than crossing the street without looking both ways. The purpose of the liturgical assembly and service is to deliver the saving gifts of our crucified and risen Lord. However, so much of what happens when the liturgy du jour occurs is an engineered experience to produce a certain mood or sensation. The projection screen helps enable this to higher degree in many cases. Psychological and social sciences along with propaganda devices enable not catechesis but manipulation of image and emotion.
3. Regarding the displacement of books and printed material.
Certainly the use of printed material is well-within the biblical orthodox tradition, whether scrolls or codices, or modern bound books. Computers and high quality printers make this easier than ever. There is also something reflective of the incarnation and the sacraments in their physical, earthly, tangible character (see 1 John 1:1-5; John 1:14). Many a bookworm could muse freely on the texture, weight, smell, and even the sound of a book as pages are turned within one's own hands, especially as books age. One could argue that the displacement of printed books with electronic media, has furthered the shortening of the attention span in western culture and narrowed our vocabulary. This certainly impacts our catechesis and the nurture of faith in terms of both trust and content (fides qua and fides quae). A book or a printed bulletin may easily be taken home and referred to again and become an object of discussion beyond the initial presentation. By comparison, the permanence of a printed Bible or Catechism or hymnal presents an opportunity for ongoing reference, discussion, study, teaching, and prayer, with or without electricity or a projector technician, while the electronic text or artwork is relatively disincarnate, and is only virtually there. In such cases is the medium or the text itself primary? Will we become like Christians in the medieval church who thought it benefited them to merely watch the spectacle Mass rather than receive Christ's body and blood given for the forgiveness of sins?
4. Regarding the visual displacement of altar and cross.
Certainly the use of projection screens at the very least means an alteration of the chancel architecture and new focal point. Prior to projection screens, the classic Christian tradition saw the altar and cross a united focal point for quite theological reasons: We preach Christ and Him crucified. This is surely even more consequential than when televisions became the focal point of the American household's family room, now with even bigger screens and louder sound systems and integrated computers. Screens in the sanctuary (holy place) cultivate the atmosphere of the living room, concert hall, karaoke bar, and sports arena. After demonizing television for so many years why invite it in with its ever-expanding creep of questionable and indiscriminate content. We live in the world and are not of it– we whose citizenship is in heaven among angels, archangels and the saints who have gone before us. Connected to an internet or satellite feed, such screens open up no end trouble for heresy and idolatry (Revelation 13:15) and indiscriminate borrowing from heterodox societies and fellowships that would deny our genuine confession of the unchanging faith (Jude 3).
What has been noted above is certainly not exhaustive by any means. Christianity is spiritual not at the expense of or negation of the physical and tangible. We confess a Savior who came back bodily alive from the grave. And this Savior is the eternal Word of the Father who became flesh in order to submit Himself perfectly under the law in humility and suffer as the holy sacrificial Lamb. The Temple and its predecessor were very earthy and tangible places. Christianity does not become less tangible or more ethereal but rather universal and sacramental so that the Word who became flesh and redeemed us may go out into the whole world until the new creation is revealed. Let us keep our eyes fixed on Jesus, the author and perfecter of our faith as He comes and serves us in His holy Word and Sacraments. My prayer is that more discussion and theological consideration of this somewhat prevalent practice may take place and we pause to consider whether we ought to use such technology in the liturgical context or reserve it for other uses with thoughtful care. Perhaps we might even consider back-tracking down the road we have gone, when our eyes were fixed on shiny new equipment the neighboring churches had. Certainly technology can be a great and useful gift within the Church in this world, but how and where it is used can be at least as important and using the latest thing certainly need not be inevitable. My own personal opinion is that technology can be best used in the church in the context of education or catechesis rather than in the liturgical realm. It can also be used well in outreach and catechesis beyond the church building with streaming audio and video, podcasts, informative websites, tracts, and online education as a component of the larger realm of residential education and parish catechesis.