The status of Hajj in Islam, and the conditions of it being obligatory
Question

What is the status of Hajj in Islam? And for whom is it obligatory?.
Praise be to Allah.Hajj to the sacred House of Allah is one of the pillars of Islam and one of its most important fundamentals, because the Prophet (peace and blessings of Allah be upon him) said: “Islam is built on five (pillars): the testimony that there is no god but Allah and that Muhammad is the Messenger of Allah, establishing regular prayer, paying zakaah, fasting Ramadaan and performing pilgrimage to the sacred House of Allah.”  
It is obligatory according to the Book of Allah and the Sunnah of His Messenger (peace and blessings of Allah be upon him), and according to the consensus of the Muslims. Allah says (interpretation of the meaning): 
“And Hajj (pilgrimage to Makkah) to the House (Ka‘bah) is a duty that mankind owes to Allah, those who can afford the expenses (for one’s conveyance, provision and residence) ; and whoever disbelieves [i.e. denies Hajj (pilgrimage to Makkah), then he is a disbeliever of Allah], then Allah stands not in need of any of the ‘Aalameen (mankind, jinn and all that exists)”
[Aal ‘Imraan 3:97]
The Prophet (peace and blessings of Allah be upon him) said: “Allah has enjoined the Hajj upon you, so perform Hajj.” And the Muslims are unanimously agreed upon that. It is something that no Muslim has any excuse for not knowing. Whoever denies that it is obligatory and he is one of those who live among the Muslims, is a kaafir. A person who fails to do it out of negligence is in grave danger, because some of the scholars said that such a person is a kaafir. This view is narrated in one report from Ahmad, but the correct view is that neglecting deeds does not make a person kaafir except in the case of prayer. ‘Abd-Allah ibn Shaqeeq (may Allah have mercy on him) – who was one of the Taabi’een – said: “The companions of the Messenger of Allah (peace and blessings of Allah be upon him) did not regard omitting any action as kufr except prayer.” The one who neglects to do Hajj until he dies is not a kaafir according to the correct view, but he is in grave danger. 
The Muslim has to fear Allah and hasten to perform Hajj once he meets the conditions of it being obligatory, because we must hasten to perform all obligatory duties unless there is evidence to the contrary. How can a Muslim accept to forsake going to Hajj to the sacred House of Allah when he is able to do it and it is easy for him to get there? How can he delay it when he does not know whether he will be able to get there after this year? He may become unable to go after he was able, or he may become poor after being rich, or he may die when Hajj was obligatory for him, then his heirs may neglect to make it up on his behalf. 
The conditions of Hajj being obligatory are five: 
1 –  Being Muslim, the opposite of which is being a kaafir. The kaafir is not obliged to do Hajj, rather if a kaafir were to do Hajj, it would not be accepted from him. 
2 – Being an adult. If a person has not yet reached the age of puberty, Hajj is not obligatory for him. If he does Hajj it is valid and counts as a voluntary Hajj, and when he reaches adulthood he must do the obligatory Hajj, because Hajj before puberty does not fulfil the obligation. 
3 – Being of sound mind, the opposite of which is insanity. The one who is insane is not obliged to do Hajj, and Hajj cannot be done on his behalf. 
4 – Being free. A slave is not obliged to perform Hajj, but if he does Hajj it is valid and counts as a voluntary Hajj. If he is set free, it is obligatory for him to perform the obligatory Hajj, because Hajj done before being set free does not fulfil the obligation. Some of the scholars said that if a slave performs Hajj with the permission of his master, this is valid and he does not have to repeat it. This view is more correct. 
5 – Being able, financially and physically. In the case of a woman, this includes having a mahram. If she does not have a mahram, then she is not obliged to do Hajj. End quote.