How do we know sanctification is God's will for believers?

The figure of sanctification is addressed directly in 1 Thessalonians 4:3 where Paul writes, 'For this is the will of God, even your sanctification.' This assertion is foundational in Reformed theology, emphasizing that sanctification is not merely a suggestion but a divine mandate for every believer. This process of being made holy is part of God's purpose in the lives of those He has redeemed, reinforcing our transformation into Christ's image as we live out our faith. The connection between our justification before God and our progressive sanctification is vital, as it reveals the comprehensive nature of salvation that encompasses both our legal standing and our moral living.