The Word of the sermon is Christ...

"The Word of the sermon is Christ accepting and bearing human nature. It is not a new incarnation, but the Incarnation. One who bears the sins of the world. The Word of the sermon seeks to accept men, no more." 
Dietrich Bonhoeffer

"But we preach Christ crucified, a stumbling block to Jews and folly to Gentiles, but to those who are called, both Jews and Greeks, Christ the power of God and the wisdom of God." 1 Corinthians 1:23-24