Why is the concept of free will significant in Christianity?

The concept of free will is significant in Christianity as it directly challenges the doctrine of God's sovereign grace. Many in the world believe that they possess the ability to choose their own paths to salvation, thereby exalting human effort over divine grace. This belief is emblematic of the 'mystery of iniquity' and leads individuals away from acknowledging their need for God's mercy. Sovereign grace theology asserts that salvation is fully of the Lord, drawing believers to rest solely in Christ's finished work rather than their own perceived autonomy.