There are a few Quranic verses and Ahadith that preach and advise the believers of Islam to perform the hajj as a duty towards Allah. Another reason that further impresses on us the compulsion of performing the hajj is that of the five pillars of Islam, hajj is the only pillar that has an entire Surah in the holy Quran, that is the Surah Al-Hajj.
“In it are Signs Manifest; (for example), the Station of Abraham; whoever enters it attains security; Pilgrimage thereto is a duty man owe to Allah,- those who can afford the journey; but if any deny faith, Allah stands not in need of any of His creatures.” Surah Aal-e-Imran 
“And complete the Hajj or Umrah in the service of Allah. But if ye are prevented (From completing it), send an offering for sacrifice, such as ye may find and do not shave your heads until the offering reaches the place of sacrifice. And if any of you is ill, or has an ailment in his scalp, (Necessitating shaving), (He should) in compensation either fast, or feed the poor, or offer sacrifice; and when ye are in peaceful conditions (again), if any one wishes to continue the Umrah on to the hajj, He must make an offering, such as he can afford, but if he cannot afford it, He should fast three days during the hajj and seven days on his return, Making ten days in all. This is for those whose household is not in (the precincts of) the Sacred Mosque. And fear Allah, and know that Allah Is strict in punishment.” Surah Barqah 
The Ahadith that build on the argument include:
“Hurry to perform Hajj (the obligatory one), as none of you knows what may happen to him” and “Whoever wants to do Hajj, let him hasten to do so.”[Sunan Abi-Dawood, Ahmad, Ibn Majah]
“Whoever performs Hajj to this house – Ka’bah- and does not commit any obscenity and wrongdoing, he, or she, will come out as the day he, or she, was born – pure and free from sins.”[Sahih Bukhari]
A hadith says, “When a person is capable of doing the pilgrimage but does not do it, he has indeed flouted a law from the laws of Islam.” [Ibid, vol 11 p. 28].
Another noble hadith says, “One who keeps postponing Hajj until he dies, Allah will resurrect him on the Day of Judgement as a Jew or a Christian.”[ Shaykh as-Sadûq, Muhammad bin ‘Ali Ibn Babwayh, Man La Yahdhuruhu ‘l-Faqih, vol. 4, p. 266.]
Imam ‘Ali bin Abi Talib (RTA) advised about hajj by saying, “Do not neglect the pilgrimage to the House of your Lord; otherwise, you will perish.” [Ibid, vol. 11, p. 23.]
Imam as-Sadiq (a.s.) said, “If the people neglect the pilgrimage to the House, the chastisement will overwhelm them and they would not be warned [about it].”[ Ibid, vol 11 p. 22.]
Umar bin Al-Khattab (may Allah be pleased with him) once remarked: “I was about to send envoys to the towns (on the outskirts of the Muslim empire) to check on all those who have the means to make Hajj but do not perform it, in order to impose the Jizyah tax upon them.” [Reported by al-Bayhaqi; Al-Haitami declared it Sahih. In another narration the words “they are not Muslims, they are not Muslims” are included.]
In conclusion, there is overwhelming evidence that not only Hajj is a pillar of faith and is compulsory, it becomes a necessity and a need for a Muslim to remain in the circle of Islam and to keep his faith when all preconditions are met. These conditions include that the person is free and not a slave, of sound mind and body, an adult and of the means to fund the journey and stay at Mecca and that there is no imminent danger if he chooses to take up this expedition.