during the period of two to three months, from the time of deciding and preparing for hajj, to the time of returning home we can judge what great effects are produced in the heart and mind of man. the process entails sacrifice of time, sacrifice of money, sacrifice of comfort, sacrifice of several worldly affairs as well as sacrifice of many carnal desires and pleasures; and all this is simply for the sake of allah, with no selfish end. then, together with piety and virtuousness, the incessant remembrance of allah and the longing and love of him pervade the mind of the pilgrim, leaving a firm impression on him which lasts for years to come.
on reaching this sacred land he witnesses at every step the relics of those who sacrificed everything they owned in servitude and obedience to allah. they fought against the disbelievers, suffered torture, were forced to migrate from their land, went through unbearable hardship and tribulations, but ultimately elevated the word of allah and did not rest content till they subdued every false power that wanted man to become subservient to entities other than allah.
a lesson in courage and determination, which a devotee of allah can draw from these clear signs and sacred relics, can hardly be available from any other source. through the circumambulation of ka`bah (tawaf), the rehearsal of a mujahid's life consisting of the rituals of hajj (such as running between two points, and repeated departures and halts), which are combined with prayer, fasting and zakah, you will realize that these processes constitute a training or some big task which islam wants muslims to execute. for this reason, hajj has been made compulsory for those who have paid all their debts and are capable of undertaking the journey to the ka`bah so that, as far as possible, muslims in the largest possible number remain equipped at every period after having fully gone through this training.
hajj brings about immense reward. abu hurairah (may allah be pleased with him) narrates that the prophet (peace and blessings be upon him) said: "the performance of one `umrah and another expiates and blots out all the sins committed in between, and hajj mabrur (hajj performed typically according to the rules of the qur'an and sunnah) has no reward but paradise." (al-bukhari and muslim)
in another authentic hadith, ibn jurayj reports on the authority of jabir (may allah be pleased with him) that the prophet (peace and blessings be upon him) said: "this house of allah (the ka`bah) is the pillar of islam; so whosoever heads for it with the intention of performing hajj or `umrah is under allah's protection. if he should die (during this journey), he will be admitted to paradise, and if he should return home safely, he will return with reward and gain."
hajj, moreover, blots out all sins. abu hurairah (may allah be pleased with him) reports that the prophet (peace and blessings be upon him) said: "whoever performs hajj solely for allah's sake and, in the course of it, abstains from obscenity and disobedience, returns after hajj as immaculate as a child just born." (al-bukhari and muslim)
`amr ibn al-`aas (may allah be pleased with him) narrates: "when allah guided me to islam, i went to the prophet (peace and blessings be upon him) and said to him: 'o messenger of allah! stretch out your hand so that i may pledge allegiance to you.' the prophet (peace and blessings be upon him) stretched out his hand to me, but i withdrew my hand. the prophet (peace and blessings be upon him) asked, 'o `amr! what is the matter with you?' i said: 'i would like to stipulate a condition!' the prophet (peace and blessings be upon him) asked, 'what is that condition you want to stipulate?' 'it is that all my past sins be forgiven,' i said. the prophet (peace and blessings be upon him) said: 'o `amr! do you not know that embracing islam removes all the sins committed before it; that hijrah (migration in allah's cause) wipes off all sins; and that performing hajj blots out all one's past sins!"' (muslim)
`abdullah ibn mas`ud (may allah be pleased with him) narrates that the prophet (peace and blessings be upon him) said: "alternate between hajj and `umrah, for these two remove poverty and obliterate sins just as the blacksmith's bellows removes all impurities from metals like iron, gold and silver. the reward for hajj mabrur (hajj performed typically according to the rules of the qur'an and sunnah) is nothing short of paradise." (an-nasaa'i and at-tirmidhi)