When it is about the end of the world, people will become ignorant of the word of Allah (the Greatest) and the Hadith of His Prophet (PBUH). At that time, knowledge will be taken away from people and none of them will remember that their forefathers perform Solat, Zakat, and other act of worship, except some people who remember that their forefathers used to say ‘Laailaha illallaah’
This Hadith says much about the incident.
Abdullah (may he be blessed), related that the Messenger of Allah (PBUH) said, “Just before the Hour there will be days when knowledge will be raised when ignorance will descend, and when there will be much killing.” (Ibn Maajah)
Hudhaifah ibn Al-Yamaan narrated that the Messenger of Allah (PBUH) said, “Islam will perish (i.e., knowledge will perish and its traces will be effaced) like the embroideries of a garment perish, until (the time) when fasting, prayer, worship, and charity will not be known; when in one-night forgetfulness will pass over the Book (the Qur’an) and not a single Verse from it will remain on the earth.
A group of people will remain — the aged man and woman — who will say, ‘We were around when our father was upon this word: Laailaha illallaah (none has the right to be worshipped but Allah), but they
will not know what is prayer, fasting, worship, or charity.” Silah asked Hudhaifah (may he be blessed), “Why will ‘Laailaha illallaah’ benefit them when they do not know what is prayer, worship, and charity?”
Hudhaifah turned away from him, but he repeated the question three times, and all the while Hudhaifah (may he be blessed) turned away from him. When Silah asked for the third time, Hudhaifah approached him and said, “0 Silah, it will save them from the Hellfire.” And he repeated that statement three times. (Ibn Maajah)
In conclusion, People will increase in ignorance and misguidance, until life in this world ends. This is what this Hadeeth of the Prophet at, “The Hour will not arrive upon anyone who says, ‘Allah, Allah,’ and it will not arrive except upon the evilest of people.”