The character is adopted into a Wealthy family. If he is an orphan, it is a true adoption. If he has living parents, he is treated just like a son. (work with your DM to determine details)
The followers of an unheard-of-god from another land followed omens that led them to you. The omens indicate that you are to be the mate of an avatar (earthly incarnation) of their god. You disagree but are still harassed by the god's followers.
When you become an adult you learn to used a weapon (of your choice) appropriate for your culture and social standing. (work with your DM to determine details)