"... Through the insincerity of liars whose consciences are seared..." 1 Tim 4:2
"If these words refer to 'demons' then this word will mean men deceiving through th instigation of th devil. But we may also supply the words, 'of men speaking.' He now descends to a particular instance, when he says that they 'speak lies in hypocrisy,' and have their consicences seard with a hot iron. And indeed, it ought to be known that these two are so closely joined together that the former springs from the latter; for consciences, that are bad and seared with the hot iron of their crimes, always flee to hypocrisy as a ready refuge; that is, they contrive hypocritical pretences, in order to dazzle th eyes of God; and what else is done by those who endeavor to appease God by the mask of outward observances."
"The word hypocrisy must therefore be explained agreeable to the passage in which it now occurs; for, first, it must relate to doctrine, and next it denotes that kind of doctrine which adulterates the spiritual worship of God by exchanging its genuine purity for bodily exercises; and thus it includes all methods contrived by men for appeasing God or obtaining his favor. The meaning may be thus summed up; first, that all who assume a pretended sanctimoniousness are lead by the instigation of the devil; because God is never worshipped aright by outward ceremonies; for true worshippers, 'worship in spirit and truth,' (John 4:24) and, secondly, that this is a useless medicine, by which hypocrites mitigate their pains, or rather a plaster by which bad consciences conceal their wounds, without any advantage, and to their utter destruction."
John Calvin.