A.T. Robertson Commentary Romans 16:17

"Now I beseech you, brethren, mark them that are causing the divisions and occasions of stumbling, contrary to the doctrine which ye learned: and turn away from them." — Romans 16:17 (ASV)

Mark (σκοπειτε). Keep an eye on so as to avoid. Σκοπος is the goal, σκοπεω means keeping your eye on the goal.

Divisions (διχοστασιας). Old word for "standings apart," cleavages. In N.T. only here and Ga 5:20.

Those which are causing (τουσ--ποιουντας). This articular participle clause has within it not only the objects of the participle but the relative clause ην υμεις εμαθετε (which you learned), a thoroughly Greek idiom.