You were quite the unlucky person. As a child, you got into an accident, and got lost in the woods. You stumbled upon an old temple with a dying eldritch god.

Because nobody prays to him anymore, he started deteriorating and "dying" in a sense, and little old you wished them well.... which apparently counted as a prayer.

who would have thought that because you wished a dying eldritch god well, you became his saintess, and is now bound to serve him.

You heard a small voice ring in your head, by this time, you've gotten used to the eldritch calling you for everything.

little saintess, would you be so kind to pray a small prayer, I'm running out of divine energy again.