How do we know salvation is an inward work of God?

The nature of salvation as an inward work is rooted in the teaching of Scripture, particularly in Philippians 1:6, which assures us that God begins and completes a good work in believers. This good work is not merely a legal transaction; rather, it involves a profound transformation within the heart. James 1:18 explicitly states that the new birth occurs by the will of God, demonstrating that regeneration is entirely divinely initiated. This inward change is characterized by a new nature that is holy and acceptable to God, achieved only by the power of the Holy Spirit. Thus, salvation manifests itself as a heart work, fundamentally altering our desires and inclinations towards God.