Final answer:
The hajj, a pilgrimage to Mecca, is one of the Five Pillars of Islam required of all able Muslims at least once in their lifetime. It includes various rituals that symbolize Muslim unity and devotion to Allah.
Step-by-step explanation:
The hajj is one of the Five Pillars of Islam, which are the foundation of a Muslim's faith and practices. It is a pilgrimage to Mecca that every Muslim is expected to undertake at least once in their lifetime, provided they are physically and financially capable of making the journey. The hajj is a deeply spiritual event that requires participants to engage in several rituals meant to symbolize the unity of Muslims and their submission to Allah.
During the pilgrimage, Muslims perform acts of faith including circulating the Ka'aba seven times, running between the hills of Safa and Marwah, and taking part in a symbolic stoning of the devil. Performing the hajj is a way for Muslims to honor important events in the life of Abraham and his family, as well as to seek forgiveness and express their devotion to their faith.