Question: Until which time is it permissible to delay the ghusl for a person who has become junub [a person who does not have a ghusl] after performing the night prayer?
Though it is permissible for a person who has become junub after performing the night prayer to delay the ghusl until the morning prayer, it is certainly much better to perform it immediately. Hadrat Imâm-i Ghazâlî states that if one who has become junub spends a prayer’s time without performing ghusl one will be made put on a shirt of fire. If people, no matter whether they practise the daily namâzes [ritual prayers] or not, spend a prayer’s time junub, they will be tormented bitterly. For example, if one, since becoming junub after the early afternoon adhân [call to prayer], has not performed the early afternoon namâz yet, performing a ghusl becomes fard when the remaining time before the late afternoon prayer is sufficient for only the performance of the early afternoon prayer. There are uncountable blessings for those who do a fard, and those who do not perform a fard commit a grave sin.

It is declared in hadîth-i sharîfs:

(When you become impure, hasten to perform a ghusl ablution! For the Angels of Kirâman Kâtibîn are upset by the person who goes about in a state of janâbat
[the state of being junub].) [Ey Oğul İlmihali]

(Angels of Compassion do not enter a residence wherein there is a picture, a dog, or a junub person.) [Nasâî]

(Angels of Compassion do not approach a person who is drunk or junub.) [Bazzâr]

(A person who gets up in order to perform a ghusl ablution will be given as many blessings as the hairs on his body
[which means very many], and that many of his sins will be forgiven. He will be promoted to a higher rank in Paradise. The blessings which he will be given on account of his ghusl are more useful than anything in the world. Allahu ta’âlâ will declare to angels: “Look at this slave of Mine! Without showing any reluctance, he thinks of My command and gets up at night and performs ghusl from janâbat. Bear witness that I have forgiven the sins of this slave of Mine.”) [Gunya]

People who do not perform ghusl
Do people who do not perform ghusl become renegades?
Though they do not become renegades, they will have committed a grave sin. One who goes about without having ghusl cannot perform namâz [ritual prayer]. Not to perform namâzes is one of the grave sins which leads a person to kufr [disbelief]. It becomes very easy for such a person to lose the îmân [belief]. For this reason, the ghusl must not be delayed. It is stated in a hadîth-i sharîf:
(Allahu ta’âlâ declares: “Those who continue to perform these three things are My real friends. On the other hand, those who omit them are My real enemies. These three things are namâz, fasting, and ghusl from janâbat.”) [Bayhaqî]

Would there remain anything in the name of abundance and peace in a house whose owner Allahu ta’âlâ declares to be His enemy and from whom Angels of Compassion stay away?

Youngsters and ghusl
When I get up having had a nocturnal emission, I need to perform ghusl. In order not to be late for school, is it permissible, even if I may miss some namâzes in the interim, for me to perform the ghusl after school?
A person can make a ghusl in two minutes. It is harâm [prohibited] to spend a prayer’s time junub. Not to perform namâzes is also harâm. It is a rather graver sin to commit a double harâm.

Going about in a state of janâbat
My parents prevent me from performing the ghusl so often, so I go about in a state of janâbat. If people die in this state, will they have died as disbelievers?
Even if going about in a state of janâbat is a grave sin, such people cannot be called disbelievers. Not to perform namâzes is a grave sin. A person who is junub cannot perfom namâz, either. You should explain in a proper manner that you have to make ghusl.