Just treat it like a voluntarily failed save, I guess?
That was my idea as well, but then again. As the post below, the Gods are fickle. They may not want to inhabit the characters afterwards.
Yes, but would they stay rejected?Honestly, I'd go with the interpretation that the gods are fickle and once rejected would go with someone else. Since a successful save only blocks that specific god for that specific character, the character can get a different god and the god can get a different host.
I might end up saying they will have to go through a certain test to see if the characters are "willing" to accept the gods as they have already rejected some of them. DC 15 Wis - if they fail have some negative effect untill their next rest.