According to the [[Scripture]]s, and the experience of the [[saints]] of both the [[Old Testament|old]] and [[New Testament]]s, God is absolutely holy. This means literally that he is absolutely different and unlike anything or anyone else that exists. He is so unique and so perfect that his existence cannot be compared to any other existence. God is absolutely transcendent, "what he is, by ''essence'' and ''nature'', is altogether beyond our comprehension and knowledge" ([[John of Damascus]]) .

Orthodox [[doctrine]] holds that God's unity or oneness is also not merely the mathematical or philosophical concept of "one". The Church teaches God as the [[Trinity]]. One God, three persons, [[God the Father|Father]], [[Jesus Christ|Son]], And [[Holy Spirit]], each of whom ‘dwells' in the other two, by virtue of a perpetual movement of love. God is not only a unity but a union.