Jehovah Witnesses are at major intersections here. Handing out pamphlets and sketchy looking mini pies.
I look at them and shake my head in disgust when we make eye contact.

First be nice, if they don't stop then, then you have to be more blunt

Say, 'No thanks, it's not for me.'

"Sorry. I'm an atheist."

The only time I want someone ringing my doorbell is if I invited them over, it's a legitimate city or state notice to evacuate the area because of a natural disaster or other circumstance, or I order food. Otherwise, don't bother me.

I am nice with my refusal, the first time! If they persist I have a very heavy door that slams nicely!

If the pastor was ringing your bell business must be bad. You should have told him the only way to celebrate death is through a Jazz Funeral and that you would be glad to be in the second line once you found out who was leading the band. Tell him Jehovah was there earlies and you had already signed up for the revival. Just tell him your Jewish.

The same way I handle any unwanted salesperson ringing my door bell.

IF I even answer them, I will smile and tell them that I am an atheist, and have ZERO interest in hearing their religious presentation. If they try to "overcome the objection" (sales training terminology), I say "No thank you" again, and shut the door. If they cannot respect my polite refusal, I do not need to remain polite to them. I never raise my voice, nor try to argue. Reasoning does not work. Refusal to engage works out rather nicely!

Go away! Followed by the shutting of my door

"Did you see the 'No Soliciting' sign when you came into the neighborhood?. If one is expected to make contributions to your church as a member then you are soliciting. Get the fuck out of here now as you are trespassing"

I haven't had any door knockers for religious bs since I been an Atheist. (when i believed in the bs)I told them I was happy in my beliefs. Then I throw there literture in the trash. If, I have one as an Atheist, I have the notion of tear it up in front of them and slam the door shut.

I once had a couple of Mormon missionaries appear at my door. They asked if they could come in. When I said, "No", they looked stunned as I simply closed the door.

Not with ‘grace,’ anymore! Not interested, and shut the door!

Be clear, short and to the point. No need to be rude or offensive unless they are asking for it and yet, always keep in mind they know where you live and you don't have a clue where they go at night.

Actually when I told them I was Jewish I lived in Utah and was in my twenties. These days I would just tell them I am an atheist.