Cain and Grace
One of the joys for me of being at the College of Transfiguration has been hearing students deliver sermons in homiletics classes. Here is a sermon by Tebogo Monyai on Genesis 4:1-16. You can listen (turn up the volume) below or open up a pdf of her manuscript as well by clicking on the download button.

Featured image is from Monreale Cathedral, Palermo, http://www.christianiconography.info/abel.html