John Calvin on Ephesians 4:27

27. Neither give place (τῷ διαβόλῳ) to the devil. I am aware of the interpretation which some give of this passage. Erasmus, who translates it, “neither give place to the Slanderer,” (calumniatori,) shews plainly that he understood it as referring to malicious men. But I have no doubt, Paul’s intention was, to guard us against allowing Satan to take possession of our minds, and, by keeping in his hands this citadel, to do whatever he pleases. We feel every day how impossible, or, at least, how difficult it is to cure long-continued hatred. What is the cause of this, but that, instead of resisting the devil, we yield up to him the possession of our heart? Before the poison of hatred has found its way into the heart, anger must be thoroughly dislodged.