Is it sufficient for someone who has reviled the religion to say to those who heard him, "I have repented and will not return," or must he pronounce the Two Testimonies in front of them? And does the ruling differ between someone who reviled the religion out of belief and intention, and someone who reviled it as a habit that has become commonplace on his tongue?

Whoever curses the religion of Islam, knowing the word and its intent, has committed an act of disbelief (kufr) and is expelled from the faith, whether they were joking or serious. And whoever habitually curses becomes even more disbelieving. Repentance (tawbah) is done by uttering the two testimonies of faith (Shahadatayn), feeling remorse, and resolving not to return to the sin. If the cursing was done publicly, it is recommended to declare one's repentance publicly. A distinction must be made between cursing "the religion of Islam," which is an act of disbelief, and cursing "a person's religion," which might refer to the person's state or manner of religious practice. The latter does not render its perpetrator a disbeliever, but rather warrants disciplinary action.