“Those who disbelieved among the People of the Scripture and the idol-worshippers were not about to desist…” ⦗Al-Bayyinah 1⦘, and the like.
A wrongdoer earns this description by neglecting what he has come to recognize as the truth, by following what he knows to be falsehood, and by speaking without knowledge. Once the truth has become manifest to him and he stubbornly turns away from it, he is indeed a wrongdoer.
Such a person is like the obstinate disputant. The Exalted has said:
“Among people is one whose speech pleases you in worldly life, and he even calls upon Allah to witness what is in his heart, yet he is the most stubborn of opponents.” ⦗Al-Baqarah 204⦘
He has also said:
“They argue with you about the truth after it has become clear.” ⦗Al-Anfal 6⦘
and:
“There you are—those who argued about matters you had knowledge of—so why do you argue about that of which you have no knowledge?” ⦗Āl ‘Imrān 66⦘