You have never heard me make such a claim about myself, because I never have. I cannot speak for others... and without knowledge and God's direction, I strive not to do so.
On the other hand, who among us, me and you included, has the perfect vision and understanding of God so as to be able to say that no one he has ever met has not yet already overcome the world as Jesus did?
They called Jesus names accusing him about things they did not know or understand. Do we understand things better now? If our understanding is not equal to God's perhaps it is better to speak. Is biting our tongues not sometimes a good thing?
What is an idle word?
"But I say unto you, That every idle word that men shall speak, they shall give account thereof in the day of judgment.
For by thy words thou shalt be justified, and by thy words thou shalt be condemned." Matt 12:36-37
"To every thing there is a season, and a time to every purpose under the heaven:
...a time to keep silence, and a time to speak;" Ecc 3:1,7
"Then said Pilate unto him, Hearest thou not how many things they witness against thee?
And he answered him to never a word; insomuch that the governor marvelled greatly." Matt 27:13-14