“I appeal to you, brothers, to watch out for those who cause divisions and create obstacles contrary to the doctrine that you have been taught; avoid them” (v17). Though the church would soon face persecution from the outside, Paul knew that internal divisions and “obstacles” caused by bad theology were just as dangerous. Paul greeted, by name, this diverse group of believers – men and women, rich and poor – and urged them to remain unified by faith in Jesus.
Paul commended the Romans for being “obedient,” but he told them to watch out for charismatic teachers who spread harmful ideas. We protect our spiritual unity and freedom in Christ by wise thinking and moral innocence (v18-19).