"By religion I have seen the lunacy of fanatics of every denomination be called the will of god. I have seen too much religion in the eyes of too many murderers."
--Hospitaller (Kingdom of Heaven)
The Church is a worldly institution composed of human beings. It is therefore affected by the same proclivities that drive all individuals, such as the desire to get more for less.
If the Church sees the opportunity to use the force of government to advance its worldly agenda, then it will be tempted to do so.
When it does to so, the Church is like any other principle hiring strong armed agents to do its bidding.
The Church, in such situations, becomes the aggressor.