Is he who abandons the denunciation of evil with his heart considered a disbeliever?

"Whoever abandons the denunciation of evil in their heart commits a sin that warrants punishment, yet they do not exit the fold of faith; rather, their faith diminishes. Sheikh al-Islam Ibn Taymiyyah holds that abandoning the denunciation of evil by heart indicates that no faith remains thereafter that would merit reward, but this does not mean that they possess no faith whatsoever."