2 John
The second epistle of John.
1. Walk in Truth and Love
1: Interestingly, this letter is written to a woman.
4: Some children are faithful to their mother's belief. Others are not.
7: Many people deny Jesus Christ even existed. Or that if he did appear, he was just an apparition and did not truly have a physical form. We are not supposed to associate with such unbelieving or gnostic teachers.
10: I am assuming this refers to specifically teachers who don't believe in the incarnation; if you weren't allowed to greet any people who didn't believe in Jesus, then you would have to go live on a deserted island somewhere.
Today, many liberal priests and preachers may not even believe in God or that Jesus is a real man who was really born on earth. We should have nothing to do with them.