You and another player character (or a notable or popular NPC in the GM's campaign) become acquainted with each other. Select an appropriate character (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.
In adulthood you have an encounter with an unusual person, who as far as you can tell, has no home or family. You offer to help in anyway you can. After accepting your hospitality the stranger vanishes leaving a note "Your kindness will be remembered".