Allah and His messengers, saying, “We believe in some and disbelieve in others, and we seek a way in between”—such people are, in truth, the unbelievers. (al-Nisāʾ 4:150-151)

As for those who commit the major sins from the community of Muhammad—may Allah bless him and his family—if they die while affirming the oneness of Allah, they will indeed enter the Fire, yet they will not remain there forever.

The Jews are unbelievers because they rejected two noble prophets: Jesus, peace be upon him, and Muhammad ﷺ. The Christians are likewise unbelievers because they denied the messengership of Muhammad ﷺ. Therefore, anyone who says today that the Jews and the Christians are Muslims and believers, that they possess valid religions, and that the religions must be brought together through dialogue, is only mixing truth with falsehood and faith with unbelief—may Allah protect us. After the mission of Muhammad ﷺ, no religion is sound except Islam: “Whoever seeks a religion other than Islam, it will never be accepted from him, and in the Hereafter he will be among the losers.” (Āl ʿImrān 3:85)

Islam has abrogated all previous dispensations. Every human and jinn, Jew and Christian, the unlettered and the learned, Arab and non-Arab alike, have been commanded to follow the Chosen Prophet ﷺ. There is no true faith except by following this Messenger ﷺ.

Major sins are transgressions that fall below polytheism yet stand above minor faults. The rule is: every sin for which a prescribed legal punishment has been set, or that ends with a threat of wrath, curse, or Fire, or from whose perpetrator the Prophet ﷺ declared himself absolved, is a major sin, as in his statement, “Whoever…"