There is a fascinating set of overlapping chiastic structures in Rom 16, and they both have to do with the same passages:
1a) Rom 16:17-18a, Avoid those who cause divisions and offenses contrary to doctrine;
1b) Rom 16:18b, They deceive the hearts of the simple;
central axis) Rom 16:19a, For your obedience has become known to all;
2b) Rom 16:19b, I want you to be wise in what is good and simple concerning evil;
2a) Rom 16:20a, And the God of peace will crush Satan under your feet shortly.
This one reveals that causing divisions and offenses contrary to sound doctrine is the work of Satan. (More on dwelling in unity despite differences of doctrine, from Rom 14-16, is posted here.) The ruling spirits of wickedness, with which we are at war, at work in that scenario is division and disunity, offense, self indulgence and self aggrandizement and self promotion and the like, flattery, and deception. Their weapon is words. Our weapon is the Word.
The ones who are deceived, are those who are simple, or naive, or unlearned, in what is good. They have not yet learned to discern between good and evil, clean and unclean, holy and common. To defend against that, Paul desires the church to be wise in what is good; to only be unlearned in the practice of evil.
The central axis confirms that salvation by grace through faith does not preclude obedience. The church at Rome was famous for its obedience.
This passage is part of a larger chiastic structure:
1a) Rom 16:17-20a, Avoid division contrary to the gospel:
1) Rom 16:17a, Avoid those who cause divisions and offenses;
2) Rom 16:17b, Contrary to the doctrine which you learned;
3) Rom 16:18, They do not serve our Lord Jesus Christ;
4) Rom 16:19, For your obedience has become known to all;
5) Rom 16:20, The God of peace will crush Satan under your feet shortly;
1b) Rom 16:20b, The grace of our Lord Jesus Christ be with you. Amen;
central axis) Rom 16:21-23, Personal greetings;
2b) Rom 16:24, The grace of our Lord Jesus Christ be with you all. Amen;
2a) Rom 16:25-27, Encouraged to be established in the gospel:
1) Rom 16:25a, To Him who is able to establish you;
2) Rom 16:25b-26a, According to the gospel which you heard;
3) Rom 16:25b, And the preaching of Jesus Christ;
4) Rom 16:26b, Accordingly … for obedience to the faith;
5) Rom 16:27, To God who alone is wise, be glory through Christ Jesus forever.
The interesting part of this structure, to me, is the A pair. If our aim is to be established in the gospel, divisions and offenses do the exact opposite. “Establish” means “to make firm or stable.” Divisions and offenses destabilize the church and keep it on sinking, shifting ground instead of solid ground.
We saw before that those who cause divisions and offenses, use smooth and flattering words in order to deceive the simple. They preach a message, in fact, but they are not preaching Jesus Christ, as those who are true to the gospel do.
Scripture is making a contrast between division and unity, offenses and peace. Making peace, living in peace, choosing to be at peace instead of choosing to be offended when something happens, is of God. Peace is the way of wisdom. Jesus, the Prince of Peace, said, “Blessed are the peacemakers, for they shall be called the sons of God,” (Mat 5:9).
And, of course, it is through Christ Jesus that Satan will be crushed under our feet. His love, His way, His gospel, His doctrine — which is, love one another, live in peace with one another, receive ye one another, humble ourselves and become as little children, submit ourselves to the will and word of our Father, and obey Him to the laying down of our own lives — is what crushes Satan under our feet.
Amen, make us famous for that, Adonai Yeshua!