Hajj is a once-in-a-lifetime pilgrimage to Mecca for Muslims, one of the Five Pillars of Islam.
Hajj is a once-in-a-lifetime opportunity for Muslims to cleanse their sins and renew their faith.
Islamic pilgrimage is to prepare Muslim for unifying his destination towards Tawheed, starting from inner feelings reaching outer behavior.
Indeed, the number of months with Allah is twelve lunar months in the register of Allah from the day He created the heavens and the earth; of these, four are sacred.