The “cross” was the instrument of death on which the Redeemer died to make atonement for sin. As the atonement made by Christ for sin is that which especially distinguishes his religion from all others, the “cross” comes to be used to denote his religion; and the phrase here means, that they were the enemies of his religion, or were strangers to the gospel. It is not to be supposed that they were open and avowed enemies of the cross, or that they denied that the Lord Jesus died on the cross to make an atonement. The characteristic of those persons mentioned in the following verse is, rather, that they were living in a manner which showed that they were strangers to his pure gospel. An immoral life is enmity to the cross of Christ; for he died to make us holy. A life where there is no evidence that the heart is renewed, is enmity to the cross; for he died that we might be renewed. They are the enemies of the cross, in the church:
- who have never been born again;
- who are living in the indulgence of known sin;
- who manifest none of the peculiarities of those who truly love him;
- who have a deeper interest in worldly affairs than they have in the cause of the Redeemer;
- whom nothing can induce to give up their worldly concerns when God demands it;
- who are opposed to all the unique doctrines of Christianity; and,
- who are opposed to all the special duties of religion, or who live in the habitual neglect of them.
It is to be feared that at all times there are such enemies of the cross in the church, and the language of the apostle implies that it is a proper subject of grief and tears. He wept over it, and so should we. It is from this cause that so much injury is done to the true religion in the world. One secret enemy in a camp may do more harm than fifty men who are open foes; and a single unholy or inconstant member in a church may do much more injury than many men who are avowedly opposed to religion. It is not by infidels, and scoffers, and blasphemers, so much, that injury is done to the cause of religion; it is by the unholy lives of its professed friends - the worldliness, inconsistency, and want of the proper spirit of religion, among those who are in the church. Nearly all the objections that are made to religion are from this quarter; and, if this objection were taken away, the religion of Christ would soon spread its triumphs around the globe.
Albert Barnes' Notes on the Bible, Philippians 3:18