People who give speeches about religious or moral topics, often in a way that is annoying or unwanted.
Sermonizers can be seen as pushy or self-righteous.
Examples:
The sermonizers at the park kept talking to everyone about their beliefs.
I don't like when the sermonizers knock on my door to talk about their religion.
The sermonizers in the town square always want to tell people what to do.
The sermonizers at the party wouldn't stop talking about their ideas.
The sermonizers in the movie were always trying to change people's minds.
The sermonizers in the neighborhood are always trying to get people to listen to them.