The question of free will and its relationship to our physical bodies is a complex and deeply philosophical one that has been debated by scholars for centuries.
There are two main philosophical positions related to this question: determinism and indeterminism.
Determinism suggests that all events, including moral choices, are determined completely by previously existing causes. From this perspective, our choices are influenced by physical processes in our brains and bodies, which are in turn influenced by our genetics, environment, and past experiences. If determinism is true, it could be argued that we don't have free will in the sense that our decisions are always the result of factors beyond our control.
Indeterminism, on the other hand, posits that not all events are strictly determined by past events. Under indeterminism, it could be possible for us to have free will, even if we are just our physical bodies, as some events or decisions might not be wholly determined by past events or physical processes.
Another position is compatibilism, which argues that determinism is compatible with free will. Compatibilists argue that we can make free choices, even if these choices are determined by physical processes in our brains and bodies, because what matters is that our choices are the result of our own desires and intentions, and are not forced upon us by external coercion.
There is no consensus on which of these positions is correct, and it's a topic that continues to be a subject of rigorous debate among philosophers, scientists, and theologians. Ultimately, the question of whether we can have free will if we are just our physical bodies is a matter of personal belief and interpretation of the available evidence and philosophical arguments.