Augustine may have understood the shift away from paganism and toward christianity particularly well because

he was very insightful
he read widely
he met with the pope on important matters
his mother was a christian and his father was a pagan

His mother was a Christian and his father was a pagan.

Explanation:

Saint Augustine is one of the most important theologians (writing in the 5th century CE) of the Christian faith and one of the most influential thinkers of the Western tradition. It is known that his mother, Monica was a devout Christian who always prayed for Augustine´s conversion, which eventually did take place. His father, Patricius, was a pagan who in his deathbed also converted to Christianity. These two factors, along with Augustine´s genius and perspicacity, certainly made him very fit to elaborate the historical shift from paganism to Christianity.  

its b add a sentence to the middle that reflects on the writer’s experiences.

i just took the test