When it comes to the Devil, who he mentions frequently, the Pope has been preaching the truth since the beginning of his pontificate:
The Devil is more intelligent than mere mortals and should never be argued with, Pope Francis has warned.
Satan is not a metaphor or a nebulous concept but a real person armed with dark powers, the Pope said in forthright remarks made during a television interview.
“He is evil, he’s not like mist. He’s not a diffuse thing, he is a person. I’m convinced that one must never converse with Satan – if you do that, you’ll be lost,” he told TV2000, a Catholic channel, gesticulating with his hands to emphasise his point.
Go here to read the rest. Saint Thomas More in his Dialogue of Comfort Against Tribulation, which he wrote while imprisoned, has quite a bit to say about Satan including this passage which strikes PopeWatch as quite wise:
Some folk have been clearly rid of such pestilent fancies with very full contempt of them, making a cross upon their hearts and bidding the devil avaunt. And sometimes they laugh him to scorn too, and then turn their mind unto some other matter. And when the devil hath seen that they have set so little by him, after certain essays, made in such times as he thought most fitting, he hath given that temptation quite over. And this he doth not only because the proud spirit cannot endure to be mocked, but also lest, with much tempting the man to the sin to which he could not in conclusion bring him, he should much increase his merit.