From Augustine’s Confessions, speaking of an encounter with a particularly charming and well-regarded teacher of Manichaeanism:
Neither did I think that a pleasant face and a gifted tongue were proof of a wise mind. Those who had given me such assurances about him must have been poor judges. They thought him wise and thoughtful simply because they were charmed by his manner of speech.
Lies can be and often are spoken with great beauty and eloquence, and important and vital truths can be and often are spoken with awkwardness and simplicity. So many chase after this or that religious teacher or this or that politician merely because of his eloquence. May God give us wisdom by His Spirit to perceive the truth regardless of the form in which it comes.
Abstain from every form (meaning appearance or mask) of evil. – 1 Thess. 5:22