In recent decades the doctrine of salvation has become a key issue in international ecumenical conversations between Lutherans and Roman Catholics and also between Lutherans and Eastern Orthodox. The 1998 Joint Declaration on Justificationbetween the Vatican and the Lutheran World Federation is a historic milestone in those efforts. Advances in ecumenical conversations have challenged the traditional opinion according to which the Lutheran view of justification by faith has been thought to be opposed to both the Eastern Orthodox doctrine of theosis(deification) and the Roman Catholic view of justification, which also includes sanctification. In One With God Kärkkäinen points out that amidst all the differences between the East and West with regard to theological orientations and the language and concepts for soteriology, there is a common motif to be found: union with God. Both the Eastern understanding of theosisand the Western idea of justification have union as the ultimate goal. Chapters are Salvation as Union," *Justification in Recent New Testament Scholarship, - *Deification in the Eastern Orthodox Tradition, - *Justification and Deification in Martin Luther's Theology, - *Deification, Union, and Sanctification in Later Protestant Theologies, - *Salvation as Union: Towards an Ecumenical Convergence, - and *One with God: In Search of a Consensual View of Salvation. - Veli-Matti Kärkkäinen, D.Theol. Habil., is professor of systematic theology at Fuller Theological Seminary in Pasadena, California.