There is no one who bears witness that there is no god but Allah and that Muhammad is His slave and Messenger, sincerely from his heart, but Allah will forbid him to the Fire. [Al-Bukhari and Muslim]
«ما من عبد يشهد أن لا إله إلا الله، وأَنَّ محمدا عبده ورسوله صِدْقًا من قلبه إلَّا حرمه الله على النار» [متفق عليه]