The document discusses the origins and early development of Christianity and Christian art in the Roman Empire. It describes how Christianity began as an underground movement as Romans persecuted Christians. As the religion grew, early Christian art borrowed symbols from Roman art but had a simpler, more symbolic style focused on religious meaning over realism. The religion gained acceptance after Emperor Constantine converted and legalized Christianity in 313 CE, shifting the empire from pagan polytheism to monotheism and establishing Christianity as the dominant faith.