What is your Biblical support for that?
Thank you for your input. I appreciated your responses very much.
There are many verses that talk about false or fake converts, such as "wolves in sheep's clothing."
21 "Not everyone who says to Me,`Lord, Lord,' shall enter the kingdom of heaven, but he who does the will of My Father in heaven.
22 "Many will say to Me in that day,`Lord, Lord, have we not prophesied in Your name, cast out demons in Your name, and done many wonders in Your name?'
23 "And then I will declare to them,`I never knew you; depart from Me, you who practice lawlessness!' (Mat 7:21-23 NKJ)
These people were surprised Christ said they didn't know him. so they obviously considered themselves Christians.
They went out from us, but they were not of us; for if they had been of us, they would have continued with us; but they went out that they might be made manifest, that none of them were of us. (1Jo 2:19 NKJ)
Here is discussed someone who was a "part of the group" and yet it turns out they were not really a part.