One of the primary means of using Scripture in the liturgy, after the reading of it, is preaching based upon it. The primary role of the liturgy is thus underscored not only by reading it in liturgy, but in regularly commenting on it in the context of the liturgy. This is then the primary means by which the Scripture is commented on in the Church. But it is specifically liturgical; and some features of this commentary are particular to that context.
By the objective setting, I mean those features which depend not on the particulars of a given congregation or preacher or moment. We are concerned then with the ritual context in which the homily is found, the particular liturgical festival or occasion, and so forth.
A homily is intended not merely to explain a given text, but to explain it for a purpose, that is, for the purpose of its setting in that particular liturgy. A Eucharistic homily thus differs from a homily preached at an office. Preaching at an ordination differs from preaching at a funeral. Preaching in Easter differs from Christmas, and both from Lent or Advent.
There is no question, therefore, of giving a homily which simply explains a text as a written commentary might; the homily is necessarily directed to the occasion and setting. Moreover, because of the priority of liturgy in the Church, the liturgical homily, with its particular setting and role, stands over written commentary.
This is not to require that every use, to be appropriate, must be preachable. Many are not, and indeed, this is the point. It is the preachable uses which enjoy priority. The homily is not intended to give a comprehensive explanation of a text, and there are explanations of the text which are not appropriate for homiletic. Perhaps a given text is read only on a particular sort of occasion, which occasion does not provide for a given interpretation. One might suppose that this is to be lamented: that the text should be taken some other time, so that the proposed interpretation can be preached.
But this would be to understand the priority of liturgy and liturgical use incorrectly. There is no antecedent correct interpretation which it is the job of the liturgy to enact or preach. Rather, the liturgical interpretation has priority (though without replacing the other uses), and that priority has its own integrity.
Crucially, liturgical contexts are given antecedently. Except on rare occasions, one does not begin with a homily and then seek a liturgy in which to embed it; likewise, liturgical procedure chooses readings first and only then begins consideration of homiletic: and the choice is made (generally not by local communities) with regard for the entire year and not simply a single occasion.
Nothing wrong has happened because a given text is read and not homilized about, or that a homily can only say some things and not everything. This is, in fact, of the nature of liturgical preaching, and it does not mean that liturgical preaching is only of secondary importance to some understanding of the text reached before; rather, it means that liturgical preaching enjoys a priority, with these characteristics as part of why it has that priority.
Different communities differ, as do different preachers. One day it may be raining; the deceased at a funeral may be well known or indigent. Appropriate preaching is responsive to all these various changes in communities and situations.
The dynamic of liturgical preaching is driven then by the relation between the fixed text of Scripture and the dynamics of actual liturgical communities, as mediated by liturgical designers who have done their work without knowing the details of the particular community.
Different interpretations are made in a homily, as a result, depending on all these factors. What establishes the correctness of the homily must be judged by the internal canons of liturgical appropriateness, and not by fidelity to some antecedent interpretation of the text or of the particular liturgical situation. One preaches on 1 Corinthians 15 at many funerals, but the content can and should vary appropriately.
Moreover, what is said in one community about 1 Corinthians 15 may be quite different from what is said in another. This does not result in any question of which is correct, merely because they may disagree in the words spoken. The job of a homily—which is a liturgical job—is to be part of a particular ritual, just as much as the lighting of candles, playing of music, or reading of prayers.
This does not mean that all preaching is equally appropriate, of course. One must judge the homily, but the judgment must be with respect to the liturgical situation in all its particularity, rather than to some idealized reading of a text or even of a liturgical context.
Locality of Reference
Any given homily is only about certain parts of the Bible. Because of the necessarily contextual setting of a homily, there is no need for the sort of consistency required of other uses of Scripture. Because a text may have many meanings; because, that is, there may be many hermeneutical filters which could illuminate it; because there is no interpretation of Scripture prior to the homily which could judge it—there is no reason that a given text must always be given the same explanation, or even compatible explanations; still less that one text must be given an explanation compatible with that given a different text.
Two points are crucial here. First, that there is (in general) no violation of appropriate homiletic in giving different readings of the same text on different occasions, or giving readings of different texts on separate occasions which could not be joined into a single homily. This follows necessarily from the reality that there is no antecedent correct interpretation to be found, which in turn follows from the priority of the liturgical use of Scripture.
Second, this places hermeneutical filters and techniques at the service of the homilist and not as a master. Moreover, because a homilist must be attentive to the objective and subjective contexts of the homily, it is unlikely that any hermeneutical filter could be determined in advance without, on some occasion or other, producing bad homiletic. (One thinks here of those Lutheran preachers who feel constrained to preach justification by faith alone in every sermon.)
The Judgment of Homiletic
I have insisted that homiletic cannot be judged by fidelity to antecedently chosen hermeneutical criteria or preceding interpretation. I have, however, been vague and inspecific about what the criteria are which distinguish good from bad homiletic.
Homiletic, embedded in the liturgical context, must function together with that context. It cannot, therefore, operate as a challenge to the basic assumptions or mechanisms of the liturgy. (If such a challenge is necessary, then one has an obligation to stop engaging in the offending liturgy rather than enacting it while criticizing it.) This is true both for objective and subjective factors.
A homily must serve the rite, offering words that enable the hearers to more effectively participate in the liturgy. A homily which so enrages the hearers that they leave (or stay only through a mistaken sense of propriety) is a failure, even if the words would be true on some other occasion. Or rather, such a homily may be successful, but not as a homily; that is, its interpretation of text has failed to be what it should be, and thus is no longer a use or interpretation of Scripture in that community.
A homily must be responsible, both to the wider Church, and to the ongoing life of a given congregation. Even when a homilist is invited to preach in an unfamiliar community and expects never to return, the homily should be responsible as if the preacher needed to stay around and deal with fall-out, as if the preacher were prepared to be judged for the content of what is said.
Finally, a homily is not a lecture, nor is it bible study. Homilies which are so inattentive to liturgical context that they are lectures have left the liturgy entirely. Likewise, homilies which are really introductions to group bible study (so-called "dialogue sermons," for example) have deviated so strongly from their liturgical moorings that they are no longer homilies, but something else. While in both these cases they may be very good lectures or bible studies, they no longer enjoy the priority properly ascribed to the homily.
On the Use and Interpretation of Scripture: Index