The indicative-imperative structure of Paul’s thought demonstrates that the pronouncement of justification is vitally related to the new life of believers. Justification and life in the Spirit are not at loggerheads for Paul. The former is the foundation for the latter, and the joy of being right with God frees believers to obey God (Gal. 5:13–15). Nor can justification be dismissed as a legal fiction, for God’s declaration creates a new reality, so that believers are rightly related to him.
Thomas R. Schreiner, New Testament Theology: Magnifying God in Christ (Grand Rapids, MI: Baker Academic, 2008), 352.