Pagan

Pagan can mean, variously, pre-christian (e.g. ancient Greek), or post-christian but unconverted (to any type of monotheistic religion), e.g. Viking pagan, Baltic pagan, etc.

The last great pagan kingdom in Europe was that of Lithuania, which began its rise under Gedmyn in 1316 or so. Lithuania remained a pagan Kingdom until about 1387, when Jagiello, King of both Poland and Lithuania converted to Catholicism.

Pagan does not mean Heretic, as that refers to a follower of Christianity who professes a doctrine different to that of the ruling church. Neither does it mean an Infidel such as a Muslim or a Jew.

Your SCA Persona is a Pagan

Owing to late Roman influence, Christianity was widespread throughout Europe and the Mediterranean before the medieval period. However, in more remote areas, such as Britain and Scandinavia it was either uncommon or had only thinly taken hold.

Norse personas, especially early in period would be pagan, as would Germanic ones. However, owing to Christian distrust of other religions, the social pressure from the ever-growing Christian community forced pagans to be regarded as the non-conformists.

Pagan personas are allowed in the SCA, so long as one isn't over-the-top about it, and does a certain amount of research to support their persona. Remember, overt religious displays of any variety are not allowed, but whatever you do in your tent is your business.