At first glance: Neither you nor the GM seem to be co-operating with other.
You: Are playing a pathfinder game and have created a character with a built-in bias against a large swath of standard fantasy tropes. It's not obvious how far this hatred of "religious institutions and supernatural elements" goes, but it seems like it would range from being a major handicap (if he just doesn't get along with religious institutions) to potentially crippling (if, in an extreme, he doesn't believe in things that are self-evident to other denizens of the setting, and/or which are just ground-truth level true in the game.)
Even if the former, try substituting "wizards" or "elves" for the subject of his antipathy, to see how this could be very limiting.
The GM: Gave no guidance about the campaign world, but accepted as-is a character that seems destined to be beating his head against the campaign world. This sort of head-beating is usually not fun.
Here's the thing, though: In giving no guidance about the campaign or feedback for the character, this situation could be as bad or worse than we've made it sound, or it could be better. The GM could be planning a nuanced campaign where the Oracle is fallible (either mystically in his/her visions, or morally or politically in his/her decisions) or where other elements come into play to keep your character interested and viable. It could be. Or it could be just a bog-standard righteous religion against evil orcs. At this stage, you have no way of knowing.
The conversation to have with the GM is delicate, here, because a straight up question about the Oracle's motivations and fallibility might only be answerable with a spoiler that the GM is unwilling to give. I've had much better luck with asking clear but high-level questions: First, lay down your concerns ("I made my character X, Y, Z, but all I see in the game is A, B, C,") and then ask, "So given all that, do you think this character is viable? Are there things for me to do that are both fun and in-character? Or is he just going to get ground down by the campaign and be causing problems for everyone?"
If the GM is thoughtful in general and has put thought into his campaign, he should be able to answer that high-level of a question clearly, but without being forced to give spoilers.
Once you have that answer, you can decide what, if anything, to do about it.