Polite To Sinners?
One aspect of "fellowship" and "disfellowship," that seems to cause great disturbance, is its relation to association. Do I "have fellowship" with a person by doing business with him; or, if he is "disfellowshipped" may I speak to him on the street? Jesus "received" sinners and ate with them. Did he "fellowship" them? Paul went into Jewish synagogues and discussed scripture with Jews there. Did he "fellowship" Judaism?
Fellowship with God (who is Light) is contingent upon my walking in the light, whereupon my sins are forgiven and my sharing relationship with God is confirmed. But in addition to this common walk before God, where judgment is in His hands; I must decide whether or not to have a sharing relationship with other imperfect folk like myself. This sharing involved in Christian fellowship suggests common faith and goals, working to the same end. Condoning, encouraging, or entering a partnership to promote sinful activity would be fellowshipping sin. We believe neither Christ nor Paul did that, although they associated with sinful people. A subtle distinction may be seen in Paul's instructions re. meats. If one sees you sitting at meat in an idol's temple, he may think you honor the idol. He is led to do likewise, and you have harmed him (1 Cor. 8:7-f). Paul says he had rather not have meat than do that. But later he shows it is not the meat, per se, nor even the association that is wrong. He could eat meat at an unbeliever's feast if there was no "test case" made (10:25f). We must make such judgments with God's glory in mind (v.31).
When a former brother is disfellowshipped he is to be unto us "as the Gentile and publican" — i.e., as he was prior to conversion (Matt. 18:17). Christians do not snub, insult, or gossip about outsiders — do they??
We would have to leave the world to avoid association with all fornicators (1 Cor. 5:9-f), and Paul does not ask that. But he forbids eating (or other relations) with an ungodly "brother" that would seem to approve such life styles for Christians. Fair and courteous treatment for all men is not the same as fellowshipping all.