Knowing

Knowledge has two wings, Opinion, one wing. Opinion is defective and curtailed in flight.
But when the bird has been delivered from Opinion, Knowledge shows its face to him: that one winged bird becomes two winged and spreads his wings.
If all the world should say to him "You are on the way to God and following the right religion."
He will not be made more fervent by their words: his lonely soul will not mate with them;
And if they shall all say to him," You are astray: you think you are a mountain and in reality you are a blade of straw,"
He will not fall into doubt because of their taunts, he will not be grieved by their departure and estrangement from him.
No, if the seas and mountains should say to him, "You are wedded to perdition,"
Not the least jot will he fall into fantasy or sickness on account of the taunts of the scoffers."

Rumi (Vol. 3, 1513-1521)

Commentary: The self-differentiated person pays little attention to praise or criticism. All that is required to accomplish this miracle, according to Rumi, is to replace belief with experience,and to replace opinion, with knowledge.