What do I do when people knock on my door advertising to go to their church?

Tell them you're an atheist.

slam your door

You do have the option of not answering

My go-to response to proselytizers is...

Like others said, you can just ignore them until they go away. Or if they are harrassing you tell them you are going to call the police or something.

OMO! This reminds me of the TikTok vid [explicit]!!!

But seriously..consider politely declining the conversation, not answering the door, or even putting up a no soliciting sign.

Quote from bethesda

How? I'm not doing it with a paper and a Sharpie marker because of the rain.

They have actual signs created to place on your door. Cost? Less than $10.

troll them to the point of absurdity

I used to live in a heavily Jehovah's Witness area growing up. At least back then they didn't have a do not contact list, just they wouldn't try again for another few months if you asked them not to come back.

It became somewhat common in my town to answer the door fully nude after the first time because then they never came back. It was deemed legal in my jurisdiction to answer the door in the nude, but I'm sure that varies based on state etc.