I would think, in the same way you would politely turn away a salesman.
I asked myself though, how would Jesus answer that question? What came to mind is, the Golden Rule - “So whatever you wish that others would do to you, do also to them, for this is the Law and the Prophets. Matthew 7:12
If you went to someone's home to share a Bible message, and the person is not interested, how would you like them to treat you?
Would you like them to commend you for having the courage to do that, knowing that many people do not welcome your visit?
Would you like them to offer you a glass of water... or lemonade?

Or, maybe you expect that some would not respond favorably, and so, it does not matter the response. Matthew 10:11-15
I don't usually want to get rid of anyone who comes to my door, because they aren't walking on four feet, and have large teeth, and making growling sounds.

Whoever it is that visits my home, will be welcomed... unless you come in the night, when you think I am asleep... because I see people as human beings needing the gospel, and it is an opportunity for me to share it with them... regardless of which religion they belong too.
I have never seen anyone from all the more than 45,000 denominations in the world, so I never get the opportunity to talk to any of them, lest it be when I am engaging in my ministry.
I see Jehovah's Witnesses, and Latter Day Saints, only. Which is interesting.
...and they do show their teeth, but not snarling... smiling.
If Jim Jones had come knocking at my door, or any of his followers, they would not leave my house without a word of scriptural encouragement.
Jesus gave his disciples instructions on how to respond to those who are not hospitable, and he expressed how he viewed such ones.
What about us... how does Jesus view us?
If we fail to show hospitality to people, how does Jesus view us?
Are we really showing love to our neighbor, when we turn people away without trying to help them by sharing the gospel with them... especially when we are viewing them as lost souls, destined to hell, because they do not know Jesus?
What Jesus and his apostles said, tells us the answers to those questions. Luke 6:31-46; Matthew 5:43-48; Romans 12:20
God also says it is a serious sin to refuse to warn persons. He says this... Ezekiel 3:17, 18
If we can't be friendly to all people, and show real Christian love to them by sharing the gospel "with gentleness and respect" 1 Peter 3:15, something is wrong with our profession, isn't it. Isn't it just a profession?
I can go to a Latter Day Saint's, or Jehovah's Witness home, and talk with them for a long time, and they would welcome me. They never turn me away.
Why do you want to turn people away?
You don't love them?