Is it permissible to remind oneself of the Almighty's saying: "See how they strike parables for you, so they have gone astray, and they cannot find a way" when afflicted by whispers of creed, or is silence preferable?

It is prescribed for one into whose heart Satan casts whisperings to say, "I believe in Allah," and to seek refuge in Allah, and to stop the whisperings. There is no harm in reciting verses that he knows have an effect in dispelling them.