Whats contrasts does Gibbon draw in his Decline and Fall of the Roman Empire between Paganism and Christianity? In whats ways does he use Paganism either to praise or criticize the Christian religion?

Historian and scholar Edward Gibbon opines in his seminal work, The History of the Decline and Fall of the Roman Empire, that the destruction of pagan culture and history by Christian powers of the Holy Roman Empire was an act of vandalism. When Emperor Constantine literally and figuratively converted the Roman Empire into a Christian "empire," he fervently followed the Christian doctrine. This meant that many of the pagan and non-Christian cultures and belief systems that thrived in Rome were destroyed. Gibbon compared the old pagan beliefs of the Romans (i.e., Roman mythology that was a direct descendant of the ancient Greek mythology and pantheon) and Christianity in a tone that was sympathetic toward the pagans.
Gibbon believes that Christianity, or at the very least the Christian authorities, contributed to the decline and eventual collapse of the Roman Empire. There is a misconception that the fall of Rome was due to Vandals, Visigoths, and other Germanic tribes sacking the heart of the empire. However, the Roman Empire continued as a the Holy Roman Empire under Constantine.
Interestingly, Christians were heavily oppressed and persecuted by the Romans during the height of the empire, yet the Romans focused on military campaigns against the Germanic and French tribes from the north. However, in the end, it was the corruption and authoritarianism of Christian Romans who would lead to the downfall of the Roman Empire.
Gibbon argues that the pagan culture and religion of ancient Rome was more tolerant than Christianity. Ironically, many Roman emperors were not tolerant toward Christians, Jews, and Muslims. However, Gibbon believes that, unlike Christians, the ancient Romans did not use religion as a tool of colonialism and oppression. Gibbon believes that the Holy Roman Empire was even more intolerant than the old Roman Empire.
Gibbon also contrasts the rules of law and system of governance between the Holy Roman Empire and the old Roman Empire. For instance, there were examples of democratic values in ancient Rome, especially under Julius Caesar, whereas the Christians of the new Roman Empire looked to expand their powers even more. Another point Gibbon makes is that the Christians did not replace the old Roman Empire fundamentally. For instance, the Holy Roman Empire simply replaced the veneration of past emperors and deities from Roman mythology with the glorification of past Christian martyrs and saints.
https://www.ccel.org/g/gibbon/decline/volume1/chap28.htm