When people speak to us, it's imperative for us to listen. More often than not, we've already a list of responses at the tip of our tongue and the pressure to release them before their sentence is done is palpable. There is always a push behind our words and we have to be careful with the words we choose so that they aren't going after the person, but the spirit that's warranting the response. The devil is always talking, but knowing what the Lord has said and speaking that in order to establish what's true goes much further than having a witty or unnecessary rebuttal.
Ephesians 6:12 (NLT) - "For we are not fighting against flesh and blood enemies, but against evil rulers and authorities of the unseen world, against mighty powers in this dark world, and against evil spirits in heavenly places."