The conversion of Hamza did much to further the cause of the religion and restore a sense of honour and pride to the believers.

Hamza's conversion, although initially proclaimed out of anger due to the oppression of his kin, proved to be extremely fruitful in strengthening Islam and the Muslims. It came about through an incidence that occurred at the Ka'bah between the Prophet who was one day seated on the hillock of Safa when Abu Jahl passed by and insulted Islam. The Prophet kept quiet choosing not to engage Abu Jahl in his vain talk, an act which incensed him, so he took a stone and struck the Prophet's head which began to bleed. Abu Jahl then left to join the Quraysh at their assembly place. Hamzah happened to be returning from a hunting trip when a slave-girl belonging to 'Abdullah bin Jad'an, informed him of what had happened. On being deeply offended, he hastened to the Ka'bah where he found the aggressor sitting in the courtyard of the Holy Sanctuary. Hamzah rushed upon him and violently struck Abu Jahl on the head saying: "Ah! You insult Muhammad when I too follow his religion?!" His conversion proved to be a source of great strength to the Islamic Faith and its adherents, and he himself came to be known as the 'Lion of God'.

Hamza, the uncle of the Prophet, was one of the bravest men of Arabia and a well-known officer of Islam. It was he, who insisted earnestly that the army should go out of Medina and fight against Quraish in the battle of Uhud. It was Hamza, who protected the Prophet in Mecca during the delicate moments with all his might.