First, what does religion have to do with weed? Let's assume for a moment that there is a God or Gods and that those people are correct who believe God/The Gods created everything on Earth. Are they objecting to something their own God/Gods created?
Second, when they took the job they agreed to perform certain duties for which they are getting paid. If they don't want to perform those duties, they should be replaced as the article states.
This is as stupid as that county clerk who refused to issue marriage licenses to people in the LGBT community once it became law. Either get on board with the new program and do your job, or quit. It's really that simple.