Don Carson highlights the seriousness of divisiveness in the following from Showing the Spirit:
'At that last Wednesday evening, I tried to outline the three areas that could lead to the supreme sanction, excommunication: flagrantly immoral life, major doctrinal aberration, and a loveless, fundamentally divisive spirit. It was the last one, of course, that was so important in our context: "Warn a divisive person once, and then warn him a second time. After that, have nothing to do with him" (Titus 3;10). This strong response is a reflection of the New Testament's profound commitment to the unity of the church.'