About Luther supporting the state and rules rather than the rightless: he was following the (supposedly inspired) teachings of St. Paul. From Romans 13:1-2

Obey the government, for God is the one who has put it there. There is no government anywhere that God has not placed in power. So those who refuse to obey the laws of the land are refusing to obey God, and punishment will follow.

Thus, if there's a ruthless king who oppresses the people, God put the king there to punish the peasants, and the peasants deserved to be oppressed.

Of course, a lot of people think that the teaching of Jesus and the teachings of Paul are very much at odds, but pretty much all Christians of that day believed that the parts of the New Testament outside of what Jesus said was as directly from God as what Jesus said.