The church of Christ is designed to be a united body (Eph. 2:14-16; 4:4-6). Unfortunately, the Devil has servants who try to disrupt that unity through false teaching and ungodly practices. In Romans 16:17-18 Paul provides instructions for dealing with such individuals.
First, there is the command to “note,” or pay close attention, to those who cause division, and “avoid” them, which indicates purposefully keeping away from them. The rationale for this command is fleshed out in 3 points. First, consider the fruit of their actions. To cause division is to produce factions and dissension in the body, and “offenses” refer literally to setting a trap that results in division. Second, note their method. They deceive the vulnerable by “smooth words and flattering speech.” The idea is that they give the illusion of truth by saying things that sound good but actually have no merit whatsoever. Finally, Paul addresses their motive. They “serve their own belly” which means instead of being a slave of Christ, they are slaves of themselves. They are egomaniacs who are completely self-centered and do everything to serve their own appetites.
This command applies in a general way to any doctrine or practice that is false and harms the church. But consider a specific application that normally is not discussed in this context. In Romans 14 Paul discusses liberty in matters of judgment and commands Christians not to allow their judgments to become problematic in the church. But what happens when they do? It is appropriate to apply Romans 16:17-18 to Romans 14. If a person pushes an opinion to the point of causing division, they sin and should be marked and avoided. If a preacher preaches a strange doctrine that he insists is a matter of judgment, yet that doctrine is pushed to the point of causing division, then he has sinned and should be marked and avoided. The command to mark and avoid is not restricted to false teaching. It includes opinions, attitudes, speech, actions, and anything else that causes division and problems in the church. When judgment becomes doctrine, the church has no choice but to fulfill the divine imperative to “note those who cause divisions and offenses, contrary to the doctrine which you learned, and avoid them” (Rom. 16:17).