Are sermons unique in our world today? Where else do we have opportunity for one person to expect a group to listen to a talk and, conversely, for a group to gather willingly to submit to the thoughts and ideas of one person? OK - I see those answers coming: Rotary dinners, school prize-givings. But are they not single focused? We would expect the speaker to concentrate on (say) their area of specialty or the immediate context ('the school and its successful past year'). In a sermon the preacher is free to range widely, from heaven to earth, around the globe, from subject to subject. Jesus is Lord of all, so his Word potentially on any given Sunday may speak to any topic under the sun.
The sermons I heard yesterday reminded me of another aspect of sermons, which, again, is possibly unique today: the preacher has opportunity to explore a range of possibilities in how her or his context is communicated. Literary flourishes, rhetorical strategies, tonal changes, theory and testimony, principles and pragmatics. As a listener we may have the experience of hearing the simple truths of the gospel expressed in the richest of imaginative language and illustrated by profoundly deep stories.