Jesus vs. Sectarianism
Was there ever anyone with more integrity, and who made greater demands, than Jesus Christ? Yet look at the catholicity of His practice: He ate with publicans, harlots, and sinners, and He took nursing infants into His arms and thus to Himself. Who complained about all this? The Pharisees.
How could Jesus, the spotless Son of God associate with such evil people? Simple: They were (a) members of the visible church, even though that church was borderline apostate (run by Sadducees and Pharisees). They were (b) not excommunicate from that visible church. They were (c) willing to listen to what He had to say.
Now, of course, after they listened for a while, most of them departed, not willing to persevere. They excommunicated themselves. But initially, they were welcomed according to the catholic principle we have outlined. Notice that Jesus ate and drank with them. It requires a clever bit of nominalism to miss the sacramental implications of this. Pharisees, beware! — James B. Jordan, The Sociology of the Church, 15.
In a footnote, Jordan adds:
Beware indeed! Jesus reserved His most ferocious threats of hellfire for those who refuse to recognize other Christians. See Mark 9:38-50 and also Numbers 11:27-29. Jesus articulates an important principle of catholicity in Mark 9:49-50. The man who has salt in himself — the fire of self-preservation and humility — will be a peaceful man, esteeming others better than himself, and with that attitude he can correct the wayward (15n9).