Is to participate
In the evil deeds
Of such a person.”
ὁ λέγων γὰρ αὐτῷ χαίρειν κοινωνεῖ τοῖς ἔργοις αὐτοῦ τοῖς πονηροῖς.
This author said, “To welcome (ὁ λέγων γὰρ αὐτῷ χαίρειν) is to participate (κοινωνεῖ) in the evil deeds of such a person (τοῖς ἔργοις αὐτοῦ τοῖς πονηροῖς).” This author explained why they should not welcome these deceivers or antichrists. If you welcomed someone, you were participating in their evil deeds. You were an enabler to evil people. There was a guilt by association. You should not even give any kind of greetings to some one with heretical teaching. Otherwise, you are indicating that you agree or you want to participate with him in their evil ways. A greeting was considered to be an agreement or assent to the evil teaching that this person had. Do you consider a greeting as an agreement about what a person believes?