Answer:
1. He declared a general amnesty
After the conquest of Mecca, he was approached by Arab Bedouin tribes, so he organized the administration of the Arabian Peninsula and introduced taxes. Christians and Jews (the nations of the Book) retained the right to religion and their own goods, but paid a special tax to the Islamic State. Polytheists were put outside the law. This is how Muhammad created the Muslim community.
2. He cleansed Kabba from polytheistic idols and turned it into an Islamic shrine.
Ten years after moving from Mecca to Medina, the Prophet for the first time performed the Hajj, which in Arabic means goal, purpose or intention. The pilgrimage has become the fifth and last pillar of Islam, with millions of Muslims coming from all over the world every year. It is believed that Muhammad then gave a speech on the right of every person and national and racial equality.
3. Most of them accepted Islam as their religion.
The leaders of Mecca initially resisted Islam, so hostility between Mecca and Medina was very open, including the conflicts of war, but there was no total war because they realized in Mecca that resistance to Islam was futile, so a compromise agreement was reached: Muhammad recognized Mecca the position of the holy city, but Kaaba had to become the shrine of the only God Allah.
4. Syria, Palestine, Egypt and Persia.
The period of the greatest expansion of Islam occurred immediately after the death of Muhammad, during the reign of the first four caliphs. Arab Muslims went from victory to victory against two great empires on their borders - Byzantium and Persia. Both of these Empires have until recently been fighting over control of Arab countries, but after the unification of Arabs, roles have changed. The Arabs conquered the Byzantine territories of Syria and Palestine during that period, including important cities there, Jerusalem and Damascus, and soon conquered Egypt. Persia was completely conquered in the short term.
5. It reached as far as Iberian Peninsula (Spain) on the west and India on the east.
The Umayyad Caliphate continued with spectacular conquests, and the Arab Empire was extended to Spain and Morocco to the west, and to the Indus Valley to the east. The only failures of war during this period concerned the defeat of the Franks, 732 at Tours, when the expansion of the Arabs deeper into Europe was stopped, and the unsuccessful siege of Constantinople, whose walls were an insurmountable obstacle.
6. Conquests were made easier by the fact that the Arabs were united under Islam , which represent a strong military force, and in addition they were masters of the desert warfare in which theirs opponents who relied on horses could not cope with camels.
The first Arab neighbors, Byzantium Empire and Persia, were exhausted by conflicts, and the incursions of Arabs into their territories were facilitated by the large number of Semitic populations within Byzantium and Persia, who are linguistically and culturally close to the Arabs, making it easier to accept the message of Islam.