Luther on Unio Cum Christo
Although often neglected, Luther's concept of unio cum Christo in justification is a fruitful model for integrating faith and ethics. According to this model, the Christian is justified in union with Christ who is present in faith. Since Christ is the incarnation of God's self-giving love, the Christian united with Christ will in turn love her neighbor. This model of integration reveals an intrinsic connection between faith and ethics. Justification concerns not only the dyad of self and God, but also the self's relations with other persons. For Luther, loving the neighbor completes justification. Nonetheless, in both Luther's writings and for the purposes of constructive ethics, unio cum Christo is best understood not as an exhaustive account of integration, but as a helpful model for illuminating certain theological commitments, especially the importance of neighbor love to the God-relation.