The concept of deification, or union with God, is a distinctive mark of Orthodoxy and has a central role within the Eastern theological framework. Since among Western Protestants there has been a recent renewal of interest in Orthodoxy, it is not surprising that scholars are trying not just to rediscover deification, but also to identify deification in Western theology. In contrast, with regards to salvation, the Western Church has focused on the cross, and since the Reformation, more specifically on justification by faith. Although within this theological framework the doctrine of union with Christ is considered essential for gaining salvation, it has often been neglected or not taught in its full dimensions. This study examines these two key concepts in the Orthodox and Reformed traditions. Their comparison is worthwhile as it illuminates their weaknesses and strengths, which leads towards practical application for the teaching in Reformed churches as well as for dialogue with Orthodox Christians. Slavko E denci grew up in Serbia as an atheist. He became a Christian during the civil war. He studied for an MTh in Theology and World Missions at Oak Hill College, London. Slavko now works with the Baptist church in Belgrade, Serbia. He is married to Alison and they have a son.