From 100 to 600 C.E. Rome went under many changes culturally and politically. Culturally Rome adopted a new religion. Politically there was a division of the empire. With so many changes, there were a few continuities in the empire.
At first, the Roman Empire considered Christianity a threat, and they persecuted those who followed the religion. Even though the Christians were persecuted Christianity still grew largely in the empire. Eventually Constantine had to legalize Christianity in 313 C.E. and it became the religion of Rome.
Politically there was a huge change in the empire. When Diocletian became emperor of the empire in 284 C.E. he realized it was too large for one man to control. So he divided it into two halves east and west. One reason for the division was that the Roman Empire was so vast that there were too many different ideas on how to run the empire and it was impossible to make everyone happy, thus dividing the empire. In 306 a civil war broke out between the two halves, and in 324 Constantine united the two and moved the capital from Rome to Constantinople. But the emperors after him were to weak and the empire divided again in 395 C.E. Even though the Roman Empire had experienced significant changes, they surprisingly preserved many of the cultural ways. When the Byzantine Empire (Eastern Roman Empire) split, they were still able to maintain the Christian beliefs. Also the paterfamilias did not change, the father was the ruler of the household and he had control over everything.
The main cultural change was that the Romans stopped persecuting the Christians, and Christianity became the main religion. Politically the empire divided into the east and west. The things that continued were Christianity, the paterfamilias, and the Roman law(also called the 12 tables).