In the Name of Allah, The Most Gracious, Most Merciful

 In order to perform this great act of worship in a way accepted by Allah and to win His content, and to avoid spending a lot of money, and precocious time, bearing difficulties and getting back with unaccepted Hajj, after being called: "your call is not heard and yours will not be double happiness, your pilgrimage is blemished and unrewarded!"
In order not to waste his Hajj, man needs to repent before going to Hajj from all sins, whether big or small, important or not important. He should avoid any illegal gain, or sinful relation. He should give people their rights and quit sins. Above all, he should intend not to commit sins again after Hajj.
  It is very dangerous to think that Hajj effaces all sins committed before performing it. It is a great illusion
 There is an agreement among scholars that the noble as7adeth saying that a pilgrim gets back from Hajj as pure of sins as the day he was born, with his sins being forgiven, refer only to the sins between man and his Lord.. As for the sins between him and sh3er, and the rights people owe him, they are not effaced or forgiven except by paying them back to their due people or if those people forgive him.
  Hence, there are three types of sins: A sin that is never forgiven, i.e. shirk (polytheism), a sin that is not left, i.e, a sin, which is between man and other people, and a sin that is forgiven, i.e the sin between man and his Lord.

Praise be to Allah, the Lord of Creations