It is pretty clear that in Philippians 3:18, the persons Paul calls “enemies of the cross of Christ” are not those who teach false doctrine, but those whose lives have been given over to carnality. That is, he has in mind those “walk as enemies of the cross of Christ,” in direct contrast to those who “walk according to the example you have in us.” The characteristics of these persons are that they are earth bound:
Phil 3:19 Their end is destruction, their god is their belly, and they glory in their shame, with minds set on earthly things.
Paul had warned them, he says, about this kind of abandonment of the Savior. Even as he wrote, he says, he was weeping (v. 18). Note Calvin comments on Paul’s approach here:
His tears also are evidence that he is not motivated by envy or hatred of men, or by any wish to revile, or by hastiness of temper, but by godly zeal, inasmuch as he sees that the Church is miserably destroyed by such pests. It becomes us to be so affected, that when we see the place of pastors occupied by wicked and worthless men, we shall sigh, and testify, at least by our tears, that we are deeply grieved for the calamity of the Church.*
It is important, also, to note of whom Paul speaks; not of open enemies, who avowedly wanted the doctrine to be undermined, but of impostors and profligates, who trampled under foot the power of the Gospel for the sake of ambition or of their own belly. And unquestionably men like this, who weaken the strength of the ministry by seeking their own interests, sometimes do more harm than if they openly opposed Christ. We must, therefore, by no means spare them but must point them out with the finger as often as there is occasion. Let them complain of our severity afterwards as much as they choose, provided they do not allege anything against us that we cannot justify from Paul’s example.**
I’m not sure Calvin is exactly right; why do Paul’s “enemies” have to be those in ministry? Still, he is surely right concerning that “point them out with a finger” bit.
These are sound words, when all around us a version of Christianity grounded upon appetite staggers about.
*The Epistles of Paul the Apostle to the Galatians, Ephesians, Philippians and Colossians (trans. T. H. L. Parker; Grand Rapids: Eerdmans, 1965), 281.