I recently moved into a house on a hill in the woods. My driveway is barely passable. I assumed that no prosthelytizers would show up at my door.
Alas, a pair of skirted women rang the side doorbell just the other day. I stepped into the porch. They said they were there to share "the word." I turned around immediately and went back inside.
Not engaging unwelcome trespassers is not being rude or impolite. There should be no expectation of hospitality when one is not invited.
I did check later to see if they'd left any trash on or around my door. Fortunately, they did not. It would have ended up in my fire pit.

They must be getting desperate for new recruits...

i had a few of them at my door before i moved into a gated community. never found it necessary to be impolite to them or shut the door in their face. just told them i wasn't interested but did appreciate their commitment & they just left.

when i lived in japan i encountered mormons frequently at kinko's and once at my door. in the case of the door-knock, i told them i was not interested and they insisted i open the door; i was naked and told them so. they responded by calling me foul names. i reported them to their superiors and at least got an apology (and was not further called upon at home). at kinko's i got them to leave me alone by responding to the query "have you heard the story about joseph smith?" with "yes i have. have you heard the one about the rabbi?" i then proceeded to tell them a very long, detailed chassidic tale, without pausing to give them any way to interrupt. the smiles froze on their faces and they avoided me ever after, which suited me just fine!

g

There is no "maturity" in their actions, but merely the desire to spread their message by any means....

I have a demon trap at my front door

Maybe shutting the door in their faces was not the best thing to do. My Father used to invite them in and question their beliefs, then give them a sermon on his beliefs about the Catholic faith...that it was created in order to control people etc. Seemed to work, they could not wait to get out of our house.

You got free business cards..stop complaining. Now put them to good use!

I would enjoy inviting them in.
I know the Bible better than almost every Christian I have met.

I'm sure that's what Jesus would do.