The Muslim community constituted to grow after Prophet Muhammad's death. Within a few decades, vast numbers of people across three continents - Africa, Asia, and Europe - had chosen Islam as their way of life. One of the reasons for the rapid and peaceful spread of Islam was the purity of its doctrine - Islam calls for faith in only one God. This, coupled with the Islamic concepts of equality, justice and freedom, resulted in a united and peaceful community. People were free to travel from Spain to China without fear, and without crossing any borders. As millions of people embraced Islam, they brought with them the heritage of ancient civilizations like Egypt, Greece, India, Persia, and Rome. Muslims cherished these cultures' knowledge and took great pains to preserve their libraries and honor and the scholars residing in their cities. Many Muslim scholars traveled to these cities seeking knowledge. They translated into Arabic volumes of philosophical and scientific works from Greek and Syriac languages (the languages of Eastern Christian scholars), from Pahlavi (the scholarly language of Pre-Islamic Persia), and from Sanskrit (an ancient Indian language). As a result, Arabic became the language of worldly scholarship, and people migrated from all over the world to study in the Muslim Universities.