To what extent the human will is “free”
There is the misconception that Reformation churches do not believe in free will. As the debate goes, one side believes in free will and the opposing side does not, instead favoring the sovereignty of God. But this is not exactly the case. Reformed churches do believe that there is a freedom within the will of men, but not in the same way as their opponents would have you understand it.
What the will does is to simply choose or make decisions. The will makes choices based upon information that is both emotional and mental to weigh and make informed decisions about what is advantageous or beneficial to itself. Whether I choose a cookie or a granola bar is something my emotional and mental desires will formulate considering health, taste, availability and tons of other factors. Having made decisions all our lives we tend to make them in split seconds not always weighing all the factors because we believe some factors are a known constant. So then by free will the Reformed/Calvinists understand the will as making free and unforced choices about what it wants. The problem then arises in spiritual matters that man does not choose God and salvation because of sin. The nature and condition of sin is rebellion and against God, and so sees Christianity as darkness and falsely sees self as already in the light. So the problem is not with the will performing its function but that it’s wants (heart and mind) are corrupted by sin to the point that it wars against God and holiness.
As Romans 5 indicate, the Christian has the renewed, reborn, regenerated heart and mind, given by the Holy Spirit to now want and by faith cling to Christ. But in everyday life we fall short time and time again due to the struggling remains of sin. Sin is not our master and king anymore, as indicated in Galatians 5, but we still struggle with habits and selfish ambition. As to sovereignty, God does providentially control all things, and yet this does not remove our responsibility for sin. Romans 9 tells us we cannot rebuke God for how we were made or what purpose we were to fulfill in His ultimate plan. Like Judas (Luke 13) Jesus affirms that the betrayal is both the divine purpose and plan of God, and yet Judas is fully and ultimately responsible for his free actions.