The sermon for the 18th Sunday after Trinity is based on the Gospel reading, Matthew 22:34-46. Read the manuscript at iowashepherd.wordpress.com.
For more information on Law and Gospel preaching, check out https://blogs.lcms.org/2014/back-to-basics-law-and-gospel/ and https://blogs.lcms.org/2011/law-and-gospel-with-pastor-walther-10-2011/