some of the beliefs for Christianity are. one is the ten commandments . another belief is you can either go to heaven or hell. they also believed in one god and his name was Jesus! they were also monotheistic!
Martin was a man who posted a thing called 95 thesis on the church door. martin posted these because the church was steeling money from people for there indulgences . martin posted this because he wanted to make a point.
The middle ages are where the church had all the power. the church made all the rules and made people pay for there indulgences. the church would say the knew god and the BFF'S and that you had to listen to them. and if you did not listen you would goto hell.
this leads to trade. and ends up to cultural diffusion. the was a holy war between the Muslims Christians.