If you are not comfortable with the deity changing the spell there is always the possibility that the deity restricts access to spells. In this case I would say that this restriction is total and permanent.
But the power comes from your god, he has the final word how it is used, especially 9th level spells. Most of the time you get what you want but not every time. I think it is even stated somewhere in the rulebook.
This is different from enhancing spells by the deity. If the deity restricts a spell used by his priest, it is a purely internal matter between god and a chosen servant. If a god starts giving out goodies like SR breaching offensive spells he enhances powers affecting the outside world. Other gods will probably be offended by one god breaking the rules.
By the way perhaps he enhances the spells of the pious priest once in a while. Not so much as you indicated but something like empower could be ok or a spell breaches SR if the player missed by one.
But the power comes from your god, he has the final word how it is used, especially 9th level spells. Most of the time you get what you want but not every time. I think it is even stated somewhere in the rulebook.
This is different from enhancing spells by the deity. If the deity restricts a spell used by his priest, it is a purely internal matter between god and a chosen servant. If a god starts giving out goodies like SR breaching offensive spells he enhances powers affecting the outside world. Other gods will probably be offended by one god breaking the rules.
By the way perhaps he enhances the spells of the pious priest once in a while. Not so much as you indicated but something like empower could be ok or a spell breaches SR if the player missed by one.