"Christianity and Paganism, in the Anglo-Saxon Period, had a lot in common: Accepting or modifying their life, the paths that they could have were always two: Good or Evil.".
It is true that, nowadays, you can believe in something different, in something else. But do you think that being religiously different would give you the same rights that everyone else has? Although you say that every human being has liberty and rights to do what they please, do you think that the rest of the world could easily accept you if you don't belong to one of the chief religions? And worse, if that religion doesn't belong to Christianity, how do you think you"re going to be seen by others? We have to accept, although we find it difficult sometimes, that Christianity, just like in the Anglo-Saxon period, is still "controlling", somehow, the world.
In the Anglo-Saxon period, the Romans invaded Britain and imposed Christianity to all the tribes or peoples who lived there before them: Britain's tribes started to be controlled by the Roman Catholic Church. Nowadays, the Institution of the Church is still the one that controls not only Britain, but also the whole world. The relationship and differences between Christianity and Paganism in the Anglo-Saxon period can be easily defined by the Literature of the time, as well as the History. As a reference, "The Seafarer" and "Beowulf" are very representative of Pagan or Christian peoples. Also, comparing them with nowadays religions will help us have a better idea of how the ideals and thoughts of that time worked.
In the Anglo-Saxon Period, Christianity was settled by Romans, whose Church promoted peace and played an important role in unifying the English people. Christianity was based on Destiny: Existence of free will to decide which is going to be your destiny, in order to save your soul. You can choose how to build your own life; free will to choose between good or evil.