The Book of Romans ends with Paul the Apostle commending many wonderful believers and ministers of faith who spend their time being faithful examples of the Christian life and doctrine Paul has been presenting in his gospel doctrine. He interjects his commendations with an extortion to be careful not to follow the example of those who divide and hurt or teach doctrine contrary to what Paul and other apostles have taught. 

"Now I beseech you, brethren, mark them which cause divisions and offences contrary to the doctrine which ye have learned; and avoid them. For they that are such serve not our Lord Jesus Christ, but their own belly; and by good words and fair speeches deceive the hearts of the simple. For your obedience is come abroad unto all men. I am glad therefore on your behalf: but yet I would have you wise unto that which is good, and simple concerning evil. And the God of peace shall bruise Satan under your feet shortly. The grace of our Lord Jesus Christ be with you. Amen." ~ Romans 16:17-20