اِنَّ اَوَّلَ بَیْتٍ وُّضِعَ لِلنَّاسِ لَلَّذِیْ بِبَكَّۃَ مُبٰرَكًا وَّ هُدًی لِّلْعٰلَمِیْنَ۔ فِیْهِ اٰیٰتٌ بَیِّنٰتٌ مَّقَامُ اِبْرَاهِیْمَ وَ مَنْ دَخَلَهٗ كَانَ اٰمِنًا وَ لِلّٰهِ عَلَی النَّاسِ حِجُّ الْبَیْتِ مَنِ اسْتَطَاعَ اِلَیْهِ سَبِیْلًا وَ مَنْ كَفَرَ فَاِنَّ اللّٰهَ غَنِیٌّ عَنِ الْعٰلَمِیْنَ۔
HAJJ IN THE VIEW OF ISLAM
Most surely the first house appointed for men is the one at Mecca, blessed and a guidance for the nations. In it are clear signs, the standing place of Ibrahim, and whoever enters it shall be secure, and pilgrimage to the House is incumbent upon men for the sake of Allah, )upon( every one who is able to undertake the journey to it; and whoever disbelieves, then surely Allah is Self-sufficient, above any need of the worlds. (Surah Aal-e-Imran 3:96-97)
Hajj literally means 'Aim' and 'Ziyarat of the House of Allah' and special deeds there according to Islamic law (Shariah).
Hajj which means 'Ziyarat of the House of Allah' and performing certain rituals is one of the five pillars of Islam. Scholars of both sects believe that Hajj is a necessity of religion and its denier is a disbeliever. Hence one who refrains from Hajj has made Allah angry. It is said: "The Hajj of the house of Allah is obligatory on the one who can afford it. Then if one is deviated from Allah, Allah is needless of the people.
مَنْ سَوَّفَ الْحَجَّ حَتّٰی یَمُوْتَ بَعَثَهُ اللّٰهُ یَوْمَ الْقِیٰمَۃِ یَهُوْدِیًّا اَوْ نَصْرَانِیًّا۔
The Holy Prophet (s.a.w.a.) said:
"One who delays performing Hajj so much that he dies, Allah will assemble him among the Jews and Christians on the Day of Judgement." (Wasaelush Shia, Vol. 5, H. 21, Published Islamia, Tehran)
وَ اللّٰهَ اَللّٰهَ فِیْ بَیْتِ رَبِّكُمْ فَلَا تُخَلُّوْهُ مَا بَقِیْتُمْ فَاِنَّهٗ اِنْ تُرِكَ لَمْ تُنَاظَرُوْا۔
Amirul Momineen (a) says in his will:
"Do not leave the house of Allah empty untill you are alive. If the Ziyarat of the house of Allah is abandoned you will be involved in a painful chastisement without any respite." (Nahjul Balagah, Letter 47, Wasaelush Shia, Vol. 5, H. 15)