Final answer:
The first practicing Muslims were followers of Muhammad, who merged religious and political leadership roles. After his death in 632 CE, Abu Bakr was appointed as the first Caliph, to continue leadership of the Muslim community.
Step-by-step explanation:
The first practicing Muslims were the followers of Muhammad who converted to Islam during his lifetime. Muhammad, a merchant by trade, was known for his fair dealings and interactions with Christians and Jews, which influenced his teachings after he reported receiving revelations from the angel Gabriel. These revelations, which Muhammad recited to his followers, became the text of the Koran, the holy book of Islam.
After the migration to Medina, Muhammad was successful in converting many to Islam and established a religious community that merged both religious and political authority. This was because, at the time, governing and religion were deeply intertwined, and as he became the religious leader, his position naturally extended to that of a political leader as well. He became both the spiritual guide and the political head of the expanding Islamic community.
Upon Muhammad's death in 632 CE, the ummah (Islamic community) faced the challenge of choosing a successor. Although Muhammad had united the Arab tribes under Islam and had been the unequivocal leader, he did not name a successor. After deliberations, Abu Bakr, Muhammad's father-in-law, was appointed as the first Caliph, the successor, taking on the combined role of spiritual and political leadership of the Muslim community.