Final answer:
The quote reflects the view that Jesus of Nazareth was a significant agent of change based on his teachings and impact on the early Christian faith, as promoted by followers like St. Paul who believed that salvation was universally available.
Step-by-step explanation:
The quote "Christians should be ready for a change because Jesus was the greatest changer in history" is not attributed to a specific individual within the provided context but encapsulates the transformative impact Jesus had according to Christian belief. Jesus of Nazareth, a central figure in Christianity, is known to have preached a new religion of salvation and is regarded by Christians as the Son of God. His teachings promoted change and the possibility of spiritual liberation, which appealed to many, including the oppressed. Early Christians, especially influenced by St. Paul, believed in the universality of Jesus's message, arguing that salvation was available to all, not just Jews. The idea of change is therefore inherent in the foundations and spread of Christianity.