The Roman and Han empires were both very powerful, in their own rights. Although their culture and beliefs were very different, their ideology and governments were, at points, very similar. Both empires experienced a rise, plateau, and fall, which eventually changed their entire empires. One thing that was a key aspect in both societies was religion. While the Han empire brought Confucianism as a main element in daily life, the Roman’s had several different religions that each played a key role.
The Han empire trained bureaucrats formally in the teachings of Confucian philosophy. The Roman emperors were sometimes, after death, referred to as demigods. At the same time this was going on in the Roman empire, Jews and Christians were being persecuted. While the Romans had polytheism, Christianity and Judaism, the Han empire had Confucianism, Taoism, and Buddhism. The Chinese did better to make their religion more an aspect of everyday life and law, while the Romans did not care as much.
The fragmentation in religious beliefs in Rome lead to hostility among the people. In both empires the lack of stable economy and government caused the empire to be weak and so susceptible to attack and invasion. Rome was already faltering from within, with tax collection becoming corrupt and the economy slowing down, when the Germanic tribes came and invaded. What was left in the east became the Byzantine Empire. In China, the weak centralized government was very unpopular due to over taxation. The Huns then invaded, and the Chinese could not fend them off.
Unlike the Roman empire though, the Chinese bounced back a few hundred years later, in the 600s with the Sui and Tang dynasties. In both the Han and Roman empires, the people themselves had something directly to do with the decline of their societies. If a country is not stable and happy from within, it will not stand a chance to any outside invaders. While the element of religion in the Han dynasty brought the people together, it was not strong enough to hold the people together, while religions themselves caused people in the Roman empire to be against one another.