As I have been reading a book on the theology of Jon Sobrino, it was pointed out that the Bible shows that God is on the side of the poor, the slaves and the outcast. Fair enough, but what is really interesting is that two of the central stories in the Bible occur during the reign of two of the greatest empires in human history: the Egyptian and the Roman.
One can get lost in the grandeur of these ancient civilizations, but the Bible could care less about them. Instead, it focuses on God's people Israel and the way Moses delivers them out of Egypt and on God's Son Jesus as he ministers in Palestine ultimately to be murdered by the Romans. God's judgment in fact is against these systems of power that have abused God's people; in both cases, someone is sent to be a deliverer (Moses/Christ).
The Exodus story is probably the most referenced story in the Bible and some would argue that Jesus is a type of Moses in the Gospel of Matthew. Moreover, when one reads the judgment in the book of Revelation, the judgments mirror the 10 plagues of Egypt and those who are unrepentant tend to respond like Pharaoh did to Moses. That being said, one should note that if God is consistently on the side of the oppressed and ultimately humbles human empires then where will God enact deliverance and deliver judgment today...?