I wrote this sentence, but now I doubt that it is correct concerning commas.
However, this proves to be difficult because Mary declares, at first, that she is not able to seek pardon (,) but the night before her execution her attitude changes and she prays to God that he might forgive her.
First of all, there are a lot of them and I don´t and know if I need one in front of "but". It seems to be an independent clause but actually, the only sentence that makes sense on its own seems to be "this proves to be difficult"?.
I thought about doing it like this:
However, this proves to be difficult because Mary declares that she is not able to seek pardon at first; the night before her execution her attitude changes and she prays to God that he might forgive her.