Is the fornicator considered a disbeliever?

Adultery is a grave evil and a major sin, but its perpetrator is not considered a disbeliever. The proofs for this are: The consensus of theh Ahlus-Sunnah is that the perpetrator of a major sin does not disbelieve unless it is shirk (polytheism). Also, the hadith of 'Ubadah ibn As-Samit concerning the pledge of allegiance, which states that whoever commits a sin and is punished for it, then it is an expiation for him, or his affair is left to Allah, which indicates that he does not disbelieve. And the hadith of Abu Dharr from the Prophet, peace and blessings be upon him, that whoever dies without associating anything with Allah will enter Paradise, "even if he committed adultery and even if he stole."