Free will contradicts theism because a creator God necesarily prohibits free will.
P1: An omniscient God knows the complete history of every possible universe; (by necesity including all choices made every universe)
P2: A creator God decided which of the possible universes to create
C: God literally decided how history would turn out and what choices people would make
There is no way around this conclusion. God decided to create a universe where Adam and Eve would eat from the fruit of knowledge. God decided that Adam and Eve would sin, because literally nothing is outside his controll. By definition, nothing happens that conflict with God's decisions. Adam and Eve did not have free will; their choice was no more free than a clock is to show the correct time or not. The creator of the watch is responsible for the watch dysfunctioning, not the watch istself. Blaming a human for a crime is like blaming a gun for a murder --- sure it was the gun who shot the bullet, but the gun was controlled by someone else. This is just an analogy of course, but the point is important.
The problem of evil is so often dismissed without further elaboration by pointing to free will, and that humans (and/or demons), not God, cause evil and suffering in this world. When used to solve the problem of evil free will is nothing short of magic being invoked to dodge the disturbing implications of God's magic.
If we remove the "magic" from the equation we can confidently say that all humans have choice --- but that CHOISE IS NOT FREE FROM EXTERNAL CONTROLL AND CAUSALITY