Importance of Hajj in Islam is that Hajj is one of the most important pillars of Islam.
وَ لِلّه عَلَى النّاسِ حِجُّ الْبَیْتِ مَنِ اسْتَطاعَ اِلَیْهِ سَبیلاً.
It is on people for the sake of Allah to perform Hajj of his house, anyone who is able to undertake the journey to him. (2:196)
And it says below this verse:
وَ مَنْ کَفَرَ فَاِنَّ اللّهَ غَنِىٌّ عَنِ الْعالَمینَ
And anyone who disbelieves (and renounces Hajj, has impaired himself), Allah is not in need of any of his created ones in the worlds.”(3:97)
The sentence “It is on people for the sake of Allah …” adding the definition of “disbelieves” (infidelity) for people who renounce the obligatory Hajj. This clears shows it’s extraordinary importance in Islam.
It is interesting that in the interpretation of the holy verse:
وَ مَنْ کانَ فى هذِهِ اَعْمى فَهُوَفِى الاْخِرَةِ اَعْمى وَ اَضَلُّ سَبیلاً.
And anyone who had been blind (from seeing Allah) in this world, will be blind in the hereafter and more deviant from the path”. (17:72)
It has been quoted from Imam Sadiq (a.s.) that one of the meanings of the verse is that a person who postpones his obligatory Hajj continuously until his death arrives (he will be blind in the hereafter).1
We read in a Hadith from Imam Sadiq (a.s.): “Persons who perform Hajj and Umrah are guests of Allah. and if they die in this way Allah will forgive all of their sins”.
Also, we read in another Hadith that:
اِنَّ الْحَجَّ المَبْرُورَ لا یَعْدِلُهُ شَىءٌ وَ لا جَزاءَلَهُ اِلاَّ الجَنَّة.
Nothing compares with the accepted Hajj and it has no reward other than heaven!”
وَ اَنَّ الْحاجَّ یَکُونُ کَیَوم وَلَدَتْهُ اُمُّه.
A Person who performs Hajj purifies himself from sins like the day that he was born”.
And this is the greatest gift, and the best honor and the highest reward.