We must take our precautions of that Day, because it is a very mighty Day as Allah (swt) says:

 يَا أَيُّهَا النَّاسُ اتَّقُوا رَبَّكُمْ ۚ إِنَّ زَلْزَلَةَ السَّاعَةِ شَيْءٌ عَظِيمٌ (1) يَوْمَ تَرَوْنَهَا تَذْهَلُ كُلُّ مُرْضِعَةٍ عَمَّا أَرْضَعَتْ وَتَضَعُ كُلُّ ذَاتِ حَمْلٍ حَمْلَهَا وَتَرَى النَّاسَ سُكَارَىٰ وَمَا هُم بِسُكَارَىٰ وَلَٰكِنَّ عَذَابَ اللَّهِ شَدِيدٌ

(O mankind, fear your Lord. Indeed, the convulsion of the [final] Hour is a terrible thing (1) On the Day you see it every nursing mother will be distracted from that [child] she was nursing, and every pregnant woman will abort her pregnancy, and you will see the people [appearing] intoxicated while they are not intoxicated; but the punishment of Allah is severe.) (Al-Hajj: 1-2)

(… فَكَيْفَ تَتَّقُونَ إِن كَفَرْتُمْ) (Then how can you fear, if you disbelieve…): How can the disbelievers protect themselves against such a horrible Day while they disbelieve in Allah (swt), His Messenger and the Quran? This Day is certainly will come, Allah (swt) describes it, saying:

(  يَوْمًا يَجْعَلُ الْوِلْدَانَ شِيبًا… ) (…a Day that will make the children white- haired?): Grey hair does not appear in the worldly life at young age, rather it appears at old age. On the Day of Judgement, young children will go grey because of the terrifying events they see and when Adam (PBUH) is ordered to bring forth the group of hell, as the Prophet (saws) said:

“Allah will say (on the Day of Resurrection), ‘O Adam.’ Adam will reply, ‘Labbaik wa Sa`daik’, and all the good is in Your Hand.’ Allah will say: ‘Bring out the people of the fire.’ Adam will say: ‘O Allah! How many are the people of the Fire?’ Allah will reply: ‘From every one thousand, take out nine-hundred-and ninety-nine.’ At that time children will become hoary headed, every pregnant female will have a miscarriage, and one will see mankind as drunken, yet they will not be drunken, but dreadful will be the Wrath of Allah.”[1]

[1] Sahih al-Bukhari, Book of the Prophets, Chapter: The story of Gog and Magog, Hadith No. 3348.