The secrets behind pilgrimage are really quite unfathomable!
But before I explain the importance of this practice let us share some words from the Rasul of Allah (saw).
Narrated by Hadhrat Ali (ra):
The Rasul of Allah (saw) said, “Whoever possesses provisions and a mount that would enable him to reach the House of Allah, but does not do Hajj, it would not matter if he dies as a Jew or a Christian, because Allah says in His Book:
“Pilgrimage to the House (Kaaba) is the right of Allah (the qualities of the Names in one’s essence) upon all people who have the means to undertake it.” [Tirmidhi]
* * *
Ibn Omar (ra) narrates:
A man came and asked the Rasul of Allah (saw):
“What makes Hajj compulsory O Rasul of Allah?”
The Rasul answered:
“Provision and mount (i.e. enough food for the trip and a means of transportation).” [Tirmidhi]
* * *
An Umrah is expiation for the sins committed between it and the next, and a Hajj Mabrour that is accepted will receive no other reward than Paradise.” [Muslim]
* * *
Abu Huraira reported Allah's Messenger (saw) as saying:
“He who visits this House (Ka'ba) (with the intention of performing Pilgrimage), abstains from intercourse, and neither speaks indecently nor acts wickedly will return (free from sin) as on the (very first day) his mother bore him!” [Muslim]
* * *
Narrated by 'Abdur-Rahman bin Ya'mar:
I was next to the Rasul of Allah (saw) while he was waiting at Mount Arafat when a few men from the people of Najd approached and asked, “O Rasul of Allah, what (how) is hajj (pilgrimage)?
The Rasul of Allah (saw) said:
“The Hajj is Arafat. Whoever sees (attends) the Arafat before the rising of Fajr, then he has performed the Hajj. The days of Mina are three. But whoever hastens to leave in two days, there is no sin on him, and whoever stays on, there is no sin on him either.”
After this he sent a man to announce this to the people. [Ibn Maja, Tirmidhi, Abi Dawud, Nasa’i]
* * *
Narrated by ibn Mirdas as-Sulami (r.a.):
“The Rasul of Allah (saw) prayed for forgiveness for his ummah on the evening of the day at (Mount) Arafat. He was told, “I have forgiven them all, except the oppressor, from whom I will indeed collect the due of the one whom he wronged.”
Rasulullah (saw) said;
“My Rabb, if you will you can grant (the due from) paradise to the wronged and forgive the oppressor…”
No response came that evening.
The next day at Muzdalifah he repeated the supplication, and this time his prayer was accepted.”
Abbas ibn Mirdas said, “Upon this the Rasul of Allah (saw) laughed and Abu Bakr (r.a.) and Umar (r.a.) said to him, ‘May my father and mother be ransomed for you! This is not a time when you usually laugh. What made you laugh? May Allah make your years filled with laughter.’
‘The enemy of Allah, Iblis, when he heard that Allah answered my prayer and forgave my ummah, took some dust and started to scatter it on his head, uttering cries of woe and doom, and what I saw of his anguish made me laugh.’” [Sunan Ibn Majah]
As for the scientific aspect of hajj, the key lies in the phrase, “Hajj is Arafat”. For the House of Allah, Kaaba, can be visited at all times during the year, a practice that is called ‘Umrah’. Even though the benefits of Umrah are extensive, it is not equal to hajj.
What is the great secret behind hajj that the Rasul of Allah (saw) felt the need to make the warning, “He who has enough provision and a mount yet does not perform pilgrimage will die as a Jew or a Christian”?
This totally renders invalid the popular convention that pilgrimage is best done after one buys a house, a car, raises their kids, becomes a grandparent and retires”!
Once you can afford the provision and the means of transportation, pilgrimage becomes a fardh (compulsory) upon you.
Otherwise, you die as a Jew or a Christian.
This is profound.
 Quran 3:97