'Impostors' in the Bible

through glory and dishonor, through slander and praise; regarded as impostors, and yet true;

But evil people and impostors will go from bad to worse as they deceive others and are themselves deceived.

‘I know your deeds and your toil, and your patient endurance, and that you cannot tolerate those who are evil, and have tested and critically appraised those who call themselves apostles (special messengers, personally chosen representatives, of Christ), and [in fact] are not, and have found them to be liars and impostors;