What does Romans 16:18 mean?

Paul is offering some last-minute instruction to his readers about the dangers of false teachers. These are people who come among Christians and teach distorted versions of Christian truth as it had been taught by Paul and the other apostles. Paul had encountered such deceivers in many places, though it is not clear if they had reached the church in Rome, yet. It is also not clear which specific false teachings Paul is thinking of.

One temptation faced when encountering false teachers is to think they are sincere Christians who are simply offering a slightly different view, perhaps a better understanding, of the same great truths. Paul rejects that idea. The false teachers he has in mind do not in any way serve Christ. Instead, they serve their own appetites.

Perhaps by appetites, Paul means to show that these false teachers are most interested in sensual experiences, referring to literal appetites for food, drink, sexual experience, and money. Or perhaps he means that their end goal is to use deception to eventually gain financially from their false teaching, increasing their ability to serve their appetites. Most importantly, they do not serve the Lord.

The real problem with the false teachers is that they are effective. Those young or immature in their faith in Christ are most vulnerable to their attack. These teachers are good talkers, smooth and articulate and convincing. They use flattery, heaping on the compliments and false respect. Those not experienced with this sales tactic buy in and are deceived, led away from the truth and faith in Christ.

Paul's prescription from the previous verse stands. Believers must avoid these deceptive teachers. Engaging with them and allowing them to linger in the community is too dangerous for the church (Galatians 1:8–9; 1 Timothy 6:3–4).