How to use Scientific Methods to verify “Free Will”?

If the “original sin” of human beings is due to disobedience to the Lord’s command and stealing the forbidden fruit, then the root of “original sin” is that human beings have “free will” to choose. What is “free will”? You are welcome to watch the following youtube video analyze. The choices made by human beings can be rational or emotional decisions based on their own values and experiences, and through the analysis of the brain’s neural network and synaptic connections. However, some difficult decisions cannot be analyzed by the neural network, and the final decision will be random, or random, and it will depend on fate.