Ibn Battuta was an Islamic scholar and traveler who crossed throughout the Dar al-Islam (Islamic World), seeing how Islam has spread and adapted to different civilizations. In his travels he went throughout Central Asia, North Africa, India, East and Southeast Asia.
Islam is a monotheistic faith that treats all its practitioners as equals. All followers, or Muslims, must follow the Five Pillars of Islam: Shahadah, or the affirmation of faith (there is no God but God (Allah), and Muhammad is his Prophet); Salat, or prayer five times a day facing Mecca; Zakat, or charity/alms-giving to the poor and those in need; Sawm, or fasting during the Holy Month of Ramadan; Hajj, or the pilgrimage a Muslim must make to Mecca once in his/her lifetime if able.
What is attractive about Islam is this egalitarianism; all are equal in the eyes of God, and all practice this community-building religion. When Muslims around the world pray towards Mecca, or fast, or make their pilgrimage, they are joining a community of believers and followers. Although all Muslims follow the Five Pillars, Islam can look radically different throughout the Islamic World.
In his travels, Ibn Battuta wrote extensively about the people and civilizations he saw as well as how each region adapted Islam. For example, when he wrote about the plague when it spread to Damascus, he noted that:
(As a result of the plague) the people fasted for three successive days...(Afterward they) assembled in the Great mosque until it was filled to overflowing...and spent the night there in prayers...Then, after performing the dawn prayer, they all went out together carrying Qur’ans in their hands. The entire population of the city (of Damascus) joined...The Jews went out with their book of the law and the Christians with the gospel...(all) of them in tears...imploring the favor of God through His Books and His Prophets. (Ibn Battuta, Travels in Asia and Africa, 1325-1354)
We can draw a lot about Islam from this passage. First, we can assume that, because people were dying from plague, they would have been scared. We know from European sources that many Europeans lost faith and turned their backs on the Church and its teachings about morality and propriety. But the Muslim response was different, as it encouraged Muslims to turn inwards to their faiths to look for salvation. It is also worth noting that this passage shows Muslims and dhimmi, or people of the book (Jews and Christians) joining together to ask God for help against the plague. This shows a sense of togetherness and global appeal.
In addition to this source, Ibn Battuta shows Islam's global appeal when he visits a Muslim section of the Chinese city of Hangzhou:
The Chinese are all infidels: they worship idols, and burn their dead just like the [Hindus]. The King of China is a Tatar, and one of the descendants of [Chinggis] Khan...In all the Chinese provinces, there is a town for the [Muslims], and in this they reside. They also have cells, colleges, and mosques, and are made much of by the Kings of China...
When we approached this city [of Hangzhou] we were met by its judge, the [elders] of Islamism, and the great merchants. The [Muslims] are exceedingly numerous here. This whole city is surrounded by a wall; each of the six [districts of Hangzhou] is also surrounded by a wall. In the first reside the guards, with their commander. I was told that, in the muster-rolls, these amount to twelve thousand… In the second division are the Jews, Christians, and the Turks who worship the sun: these are numerous, their number is not known: and theirs is the most beautiful city. Their streets are well disposed, and their great men are exceedingly wealthy. There are in the city a great number of [Muslims], with some of whom I resided for fifteen days; and was treated most [honorably] (Ibn Battuta, Voyages, 1332-1346 CE)
His use of the word "infidel" shows his bias against non-Islamic faiths, but despite the bias, historians can use this quote as an example of Islam's global appeal. He mentions in the first passage that the Chinese Kings "make much of" the Muslim quarter of the city, with its mosques and colleges. He adds to this in the second passage when he writes that there are many Muslim merchants and practitioners in the city who live alongside the Chinese people, Turks, Jews, and Muslims. One can infer from this passage that Muslims live in many regions, are well-respected, and are religiously tolerant of other faiths. These are all characteristics of a religion with global appeal.
Finally, Ibn Battuta makes the heart of Islam, Mecca, seem humble. This contributes to making Islam a globally appealing religion. He writes:
I got rid of my tailored clothes, bathed, and putting on the pilgrim’s garment, I prayed and dedicated myself to the pilgrimage. The inhabitants of Mecca have many excellent and noble activities and qualities. They are good to the humble and weak, and kind to strangers. When any of them makes feasts, he begins by giving food to the religious devotees who are poor and without resources. (Ibn Battuta, Travels in Asia and Africa, 1325-1354)
When he first went on his hajj (he made two pilgrimages), he notes that the people of Mecca are noble, humble, and kind to strangers. If we pair this excerpt with the first, we get the impression that most Muslims are kind to strangers, regardless of their faith; when all are dying from the plague, mosques took in Jews and Christians. When pilgrimages came to Mecca, the locals took them in.
These are only a few excerpts out of hundreds of pages worth of primary source material, but they help show that Islam was a universal, egalitarian, and globalizing religion that helped make the Islamic World expand and gain followers.