In a proselytizing religion, every faithful member is a preacher. It's not a title, it's an act of loyalty to God. The preacher works at your work, but since their faith is the most important topic on their mind, they will not miss a chance to directly or indirectly mention it at any available occasion.

(If you live in a western country, surely you know of at least one such faith, perhaps more. And to be clear, I'm not picking on those religions here, but pointing out an experience most westerners can probably relate to, that has strong similarities to the way certain political topics are handled.)