"There is a kind of 'biblical' preaching that is not so much unbiblical as trivial. Not long ago I heard a sermon on Luke 1:26-38, in which the angel Gabriel announces the birth of Jesus to the Virgin Mary. The entire sermon focused on how God sometimes does unexpected things in our lives. After all, Mary didn't expect to become pregnant in this way. The rest of the 'exposition' focused on Mary's psychological and spiritual profile in all of this. A fair bit of what was said had some sort of relation to the text; reasonable inferences were made. But none of the 'exposition,' none of it at all, focused on Jesus! Whatever interest Luke has in saying something about Mary is minor compared with his interest in telling us who Jesus is. Five minutes of the sermon reserved for some reflection of Mary's outlook might have been appropriate; the loss of Jesus was not."
-DA Carson, Preach the Word, p.178 (emphasis in original).