There are many reasons for the fall of the Roman Empire, and all of them are related to one another. The Christian religion that was adopted by the Romans made them more passive people than before, which in turn made it difficult against attackers. Money was being used for lavish parties for the governs which could have been used for the people. The people became lazy and glutinous and didn't care about the republic.

First the morals and values of the people were at a rapid decline towards the end of their empire. Crime was running ramped through streets of Rome and made it unsafe for the common folk. There were about 32,000 prostitutes that were readily available for senators, generals and basically all the big wigs of the empire. The emperors like Nero and Caligula became infamous for wasting money on lavish parties where guest ate and drank...