Hawzah News Agency – The commander of the faithful, Imam Ali peace be upon him says:

ولَقد قالَ لي رسولُ اللَّهِ صلى اللَّه عليه وآله: إنّي لا أخافُ على‏ اُمَّتي مُؤمِناً ولا مُشرِكاً، أمّا المُؤمنُ فيَمنَعُهُ اللَّهُ بإيمانِهِ، وأمّا المُشرِكُ فيَقمَعُهُ اللَّهُ بشِركِهِ، ولكنّي أخافُ علَيكُم كُلَّ مُنافِقِ الجَنانِ، عالِمِ اللِّسانِ، يقولُ ما تَعرِفونَ، ويَفعَلُ ما تُنكِرونَ.

'Verily, the Prophet (SAWA) said to me, 'With respect to my people, I am afraid neither of a believer nor of an unbeliever. As for the believer, Allah will afford him protection because of his belief and as for the disbeliever, Allah will humiliate him because of his disbelief. But I am afraid about everyone from among you who is a hypocrite in his heart and eloquent of speech. He speaks what you hold to be good but does what you dislike.'

Source: Nahj al-Balagha, Sermon 68