I don't think there really is an actual argument for free will on both sides of the argument, and that religious folks mainly use it to not look deeply into the complexities that make up ones life.
If you believe in god how can you believe in free will. Most people who believe in god also believe that he intervenes at times in their lives. That's the opposite of free will right there, it doesn't take much farther than Exodous when god hardens pharaoh's heart and makes it so he has to do all the plagues. Even if you ignore that in the bible god constantly interferes with peoples lives for better or worse, religious people also believe god is omniscient. If god knows everything, the beginning and the end then in the end of the day you are following a script that you don't know about. If the future is truly knowable then we are all just drones following whatever path the time map has for us at that given time.
If you don't believe in god or at least one who actively cares about you specifically, and you do it for evidence based reasons then you can't deny the multitude of complex forces at play at every given moment and how they interact within your life. From details like the shape of your brain, your moms financial, emotional, and physical well being while you were in the womb. The time period you were born in, where you were born, what type of food did you eat, what schools did you go to, if you were raised in a area with dangerous chemicals like lead, the well being of the people around you, and really so many things that have nothing to do with you specifically but have an effect in your life. With all those things in mind free will is laughable as a concept at the moment, especially with around 80% of the world living under $10 a day. Yea there is probably some agency and your choices can affect your life outcome but many of the things you do are not like a cartoon devil and angel on your shoulder but rather pre determined algorithms that were made when you were very little or before you were even born.
