In my opinion, "Godwoken" is just a fancy title accorded to a Sourcerer (un)lucky enough to be chosen by one of the seven gods to serve him/her. I don't think the gods choose you based on your power level (your character in the early game is a little bitch in compare to other sourcerers).
The god gives some powers to the Godwoken so he can do his job as a servant even better.
If the other gods like your services too or are desesperate, here you go : you are Divine.
