Whenever the U.S. government has trouble doing its job and accomplishing anything meaningful for the American people (which is quite frequently) a certain segment of the church begins to speak quite loudly about how the people of God have neglected their responsibilities and relegated their job to the government. They talk about how we Christians should take back the role of caregiver to the poor and needy. They talk about how we Christians must become the arbiters of morality. They talk about how we Christians should direct the use of national finances and foreign involvement. They talk about how we should be the ones in charge.
Much of this nationalistic, dominionisitic fervor has its root in the Old Testament (Hebrew Bible). We are attracted to stories of imperialism and subjugation in scripture, yet we fail to see the way power continually leads to corruption.
Following the life of Jesus, first century Christianity was a dynamic and subversive lifestyle of oppressed and marginalized people. When Christianity became the religion of the empire it began to lose its vibrancy. Persecuted Christians certainly rejoiced when first hearing that the Roman emperor was embracing their faith, but soon the oppressed became the oppressor. Before long this merger of church and state contributed to the plunge of the western world into the dark ages.
The Renaissance and the Reformation worked hand in hand to bring the Latinized world out of this stagnation. The church reformers brought a new spiritual enthusiasm that seemed to penetrate all of society. Once again though, it does not take long for the picture to turn ugly. The oppressed becomes the oppressor, the persecuted take up violence, and those who were once on the side of righteousness become more concerned with empire building and maintaining power.
This is why we must be very careful when we claim that the church should be doing the work that the government is doing. Jesus never taught his followers how to be in charge. He taught them to go the extra mile, turn the other cheek, forgive every time they were wronged, and sacrifice to the point of death for the good of others. The way of Jesus is the way of weakness above power.