Final answer:
The persecution of Muslims by the Quraish was caused by religious, political, and economic factors. The Quraish felt threatened by the Islamic message and its challenge to their existing power and beliefs.
Step-by-step explanation:
The main causes/reasons for the persecution of Muslims by the Quraish involved religious, political, and economic factors. From a religious perspective, the Quraish, who were the dominant tribe in pre-Islamic Arabia, viewed Islam as a threat to their polytheistic beliefs and the control they had over the Kaaba, a religious shrine in Mecca. Politically, the Quraish felt threatened by the growing influence of the Prophet Muhammad and his followers, as their message challenged the existing social and power structures. Additionally, there were economic concerns as the Quraish were concerned about losing their wealth and influence that were tied to their control over the pilgrimage to the Kaaba.