Eastern Orthodox Christian theology is the theology particular to the Eastern Orthodox Church. It is characterized by monotheistic Trinitarianism, belief in the Incarnation of the Logos (Son of God), a balancing of cataphatic theology with apophatic theology, a hermeneutic defined by Sacred Tradition, a concrete ecclesiology, a robust theology of the person, and a therapeutic soteriology.
Orthodox Christians believe in a single God who is both three and one (triune); the Father, Son, and Holy Spirit, "one in essence and undivided". The Holy Trinity is three "unconfused" and distinct divine persons (hypostases), who share one divine essence (ousia); uncreated, immaterial and eternal. The Father is the eternal source of the Godhead, from whom the Son is begotten eternally and also from whom the Holy Spirit proceeds eternally. The essence of God being that which is beyond human comprehension and cannot be defined or approached by human understanding.
Orthodox Christians believe the incarnate Word of God is one person in two natures, both fully divine and fully human, perfectly God (τέλειος Θεός) and perfectly man (τέλειος άνθρωπος). Throughout the ages this has been a point of contention between schismatic Christian theological factions (heterodox) and the mainstream body of Christian believers (orthodox). Christ had a divine will, or set of desires and spiritual incentives, and a human will with fleshly drives. He had a human body, human mind, and human spirit able to be tempted with sin and to suffer the same way as we would. In this way God is said to have suffered and died in the flesh of Jesus, although the divine nature is itself impassible and immortal.