Regarding heresies:
Assuredly in every one of these heresies, the devil has thus disguised himself,
and has suggested to them words full of craftiness.
The Lord spoke concerning them, that “false christs and false prophets will rise
and show great signs and wonders to deceive” many (Mt 24:24).
Accordingly the devil has come, speaking by each and saying,
“I am Christ, and the truth is with me;”
and he has made them, one and all, to be liars like himself.
St. Athanasius, To the Bishops of Egypt and Libya