Many Christian philosophers' perspective of free will is so cringe, I really was reconsidering my religious belief upon hearing them.
Just to clarify:-
• First and foremost, there are good arguments for free will from secular and religious philosophers. I've heard a few and I have to rethink and reevaluate my deterministic world view (i.e. no free will) multiple times because of them.
• Second, determinism as argued by proper philosophers is very, very robust. There is almost nothing that could crack their arguments from a logical standpoint.
When many Christian philosophers tried and failed to argue for free will, their arguments are often convoluted and illogical (not using any form of logic, whatsoever). They usually boils down to two things: moral responsibility and free will is necessary for true faith.
The Bible is not a philosophy textbook. Scripture teaches not philosophy but obedience. And by definition, obedience necessitates giving up the choice to act otherwise. How are we free if one of the precursor for true faith is obedience. And by obedience, meant we have to give up our choice to do whatever we please. Therefore, how exactly are we free?
Moral responsibility is deterministic by nature. It is the fact that you know there are consequences to your action that compiles you to act or not act. Your moral responsibility is determined by whether or not you choose to accept the consequences. Having free will necessitates that there is no known consequence to each action, even when repeated.
Many compatibilists argue that free will exist merely because we feel free when we make choices. They don't argue if it inherently exist (like, does a triangle actually exist in the physical world), they argue that if it exist in our minds, then it is all that matters.
Lastly, whenever an opposing philosopher says a disclaimer that "they may be wrong", many Christian philosophers hop on that and say "how great it is for someone to admit they might be wrong" but never do they say "Christians may also be wrong" in return. This is the most cringeworthy, if you ask me.
I'm no philosopher, I know the tip of the iceberg in the free will debate. But these Christian philosophers and pseudo-philosophers are the worst at making a good solid argument and give Christian-oriented philosophy a bad reputation.
Free will itself has nothing to do with theology. Ask any theologian worth their salt, they would agree that free will is not written in Scripture but rather a theodicy that explains the problem of evil (which is a philosophical debate argued from a religious angle).
Omni-God argument is also a philosophical/theological argument to explain why Yahweh is the one true God but has many times forced to compromise due to contradiction in theodicy. While Omni-God argument can still hold (barely) against the logical problem of evil (using free will), it crumbles when talking about the natural problem of evil.
So, regardless, it stands to reason that if you want to argue for free will, religious or not, you need to conjure up a robust philosophical argument against determinists.