This paper seeks to find the major points of the Orthodox Church`s soteriology, embedded in the concept of deification, that Protestant churches can accept. Protestant theologies of justification and soteriology had a different context and development in history from the Orthodox theology of deification. While both churches are different in theological orientation and terminology to explain the way of salvation, they share a common purpose of true relationship and union with God. Thus we need to discuss how the Protestant church can accept the Orthodox Church`s insights for salvation in the concept of deification (theosis). These insights can complement and extend Protestant soteriology. Deification was not strange to the Reformers; Luther and Calvin were well aware of the Church Fathers` idea of deification. Nevertheless, the Protestant Church narrowed the understanding of salvation down to justification alone. The theology of deification can expand our understanding of salvation as follows: First, deification helps us to better understand salvation from a wider perspective in the Bible. It helps Protestant churches expand the meaning of salvation from a human problem in relation to sin to encompass God`s purpose for creation. Moreover, Protestant churches can complement the forensic metaphor with an analogy of respectful fellowship in order to uncover the inclusive and dynamic meaning in salvation. Furthermore, Protestant churches can express more affluently the understanding of salvation according to the Orthodox Church`s insights by explaining the basis and purpose and the power and possibility of salvation in terms of the Triune God: by accepting the Orthodox Church`s insight of deification, Protestant churches can emphasize that salvation is not simply the restoration of the original state of humankind before the Fall but that it entails participation in the love and life of the Triune God.