In I Thessalonians 4, Paul begins addressing the practical issues of living a life pleasing to God. In verse 3, he says, “This is the will of God, your sanctification.” It is both God’s decretive will (His people will be surely be sanctified) and His prescriptive will (what He commands). While we are responsible to obey the Lord, we are only able to do so because we have been sanctified by the work of Christ and we grow in this sanctification by the power of the indwelling Holy Spirit.