sermonize

Short definition from Wiktionary

Verb

1. 1
   To speak in the manner of a sermon; to preach; to propagate one's morality or opinions with speech.
2. 2
   To preach a sermon to (somebody); to give (somebody) instruction or admonishment on the basis of one's morality or opinions.
3. 3
   To say in the manner of a sermon or lecture.
4. 4
   To inculcate rigid rules.