Is disfellowshipping and shunning Bible based? What does the Bible say? The Apostle John said, 'If anyone comes to you and does not bring this teaching, do not receive him into your house, and do not give him a greeting. Anyone who welcomes him shares in his wicked work.' 2 John 1:10-11 Some Bible translations do not use the word 'greeting'. They say 'welcome' or 'encouragement' or 'do not give him words of love'.
Is disfellowshipping and shunning something Jesus would have taught? No. It wasn't. Even though Jesus rebuked the Pharisees for their preoccupation with the law, self righteousness, and outward appearance instead of the love of God, there is no evidence that Jesus refused to greet people or that he treated some people as if they were literally dead. There is no evidence that Jesus taught his followers to disfellowship, shun, or hate people who left his teachings. See Apostate Jehovah's Witnesses
If John was not speaking about disfellowshipping and shunning, what did he mean in 2 John 1:10? John was simply warning Christians against publicly appearing to support teachers who oppose the message of Jesus. We know this is what John meant because 2 John 1:11 says, 'Anyone who welcomes him shares in his wicked work'. Offering food and shelter could be viewed as public approval. It would be the same today if a Christian publicly offered a contribution, donation, or 'love offering' to someone who teaches atheism.
On the other hand, being humane, saying, 'Hi, how are you?', or having a conversation with someone would not make a person guilty of 'sharing in his wicked work'.
The Apostle John was one of the twelve disciples. He observed Jesus every day and knew what Jesus taught. John knew that Jesus was the perfect example of God's love.
For example, even though Jesus disagreed with the Pharisees, he had conversations with them all the time. That didn't mean Jesus agreed with what they had to say. Greeting the Pharisees, discussing spiritual matters, and even eating with them (Luke 7:36) did not mean that Jesus 'shared in their wicked works'.