Pastors struggle to find a fresh word at Christmas. We also struggle with expressing authentic sermonic lament ("celebration" is more popular in both pulpit and pew). An old article I found buried in my file helped me with both of these homiletical challenges.
Wendy Zoba, in "Mary Rejoicing, Rachel Weeping" (Christianity Today, December 8, 1997), wrote honestly about the dark side of Christmas, the slaughter of the innocents, and linked that horrific episode with the sorrows of mothers throughout history and down to the present.
Although no mothers in my congregation (as far as I know) have lost children in a massacre, many (and not just mothers) are burdened with numerous griefs which are especially keen around the holidays. They may wonder whether God is present in the midst of their pain, as the bereaved of Bethlehem may have wondered what was going on when Emmanuel was born.
The theme of Rachel weeping gave me something unfamiliar to preach about the Sunday after Christmas and an opportunity to address pain in the pew. An additional benefit was educating the congregation on the textual connections between Genesis, Jeremiah, and Matthew.