It's not logical. You feel in your heart that you are free in your decisions, and that's enough.

If you are lucky enough you will think you have a free will all your life, and never understand people who commits "bad" acts, so think they are affected by some devils or too blinded by their worldly emotions while you are just too good at surpressing them because of your faith's power. It's just believing you are special in some supernatural way and not actually thinking about it because everyone around you does so, and your religion is too perfect and moral to be false.

Never read books from other cultures, never get out of your circle, never try to understand others, and it's all perfect. You can have literally no pity and just hatred for people who think different from you. That's the power of masses I guess. Social bonds and bias.