The Meaning of the Hadith: The Entire Ummah Will Be in the Fire Except One

Question:
This is a loose reference to the hadith of the splitting of the community and what it means: that all of them will be in the Fire except one.

Answer:
This is a warning that all of them will be in the Fire because they have departed from what they departed from, namely the Sunnah of the Messenger of Allah (peace and blessings be upon him), which the Messenger of Allah (peace and blessings be upon him) and his Companions were upon. Thus, this warning applies to them: all of them will be in the Fire. Some of them are in the Fire because they are disbelievers, if their departure necessitates disbelief. And some of them are in the Fire because they are people of major sins and open sinners, if their departure does not necessitate disbelief. Such a person is warned of the Fire, but he is not a disbeliever. And if he enters the Fire, he will not remain in it eternally. So all of them are in the Fire according to their conditions. Some of them are in the Fire eternally because they are disbelievers. And some of them are in the Fire because they are open sinners, and they are punished by the Fire like the people of major sins. Then they will come out of it by the permission of Allah (Glorified and Exalted is He), and they will not remain in it eternally with the disbelievers.
So this is a severe warning that indicates the need to be cautious of splitting and disagreement, and it encourages unity and agreement upon the Book of Allah and the Sunnah of His Messenger (peace and blessings be upon him).