In Christian theology, the doctrine of incarnation teaches that the pre-existent divine person of Jesus Christ, God the Son, the second person of the Trinity, and the eternally begotten Logos, took upon human nature and "was made flesh" by being conceived in the womb of a woman, the Virgin Mary, also known as the Theotokos. The doctrine of the incarnation then entails that Jesus was at the same time both fully God and fully human.

Christian theology is the theology – the systematic study of the divine and religion – of Christianity and Christian belief and practice. It concentrates primarily upon the texts of the Old Testament and of the New Testament, as well as on Christian tradition. Christian theologians use biblical exegesis, rational analysis and argument. Theologians may undertake the study of Christian theology for a variety of reasons, such as in order to:help them better understand Christian tenets make comparisons between Christianity and other traditions defend Christianity against objections and criticism facilitate reforms in the Christian church assist in the propagation of Christianity draw on the resources of the Christian tradition to address some present situation or perceived need education in Christian philosophy, especially in Neoplatonic philosophy