Abu Hurairah (May Allah be pleased with him) reported: The Prophet was asked: “Which deed is the best?” He (PBUH) replied, “Faith in Allah and His Messenger.” Then he was asked: “What is next?” He replied, “Jihad (holy fighting) in the Cause of Allah.” Then he was asked, “What is after that?” The Prophet replied, “Hajj Mabrur (an accepted pilgrimage).”
[Al-Bukhari and Muslim].
Commentary: This Hadith points out the fact that Hajj is one of the most prominent religious acts, provided it is done sincerely and keeping oneself away from sins. Some people have interpreted the word “Hajj Mabrur” as an accepted Hajj. They say that the sign of an accepted Hajj is that one becomes a true worshipper of Allah, which he was previously not.