Christmas is a very dualistic time in Christian churches. In stories and sermons God is pictured as a theistic deity up there in heaven who sends his Son down here into this world of sin in order to redeem the world and humankind. Those of us who see the universe in terms of nonduality wonder how to make sense of Christmas. The good news is that the heart of the Christmas message is nonduality.
The theological heart of the Christian celebration of the birth of Jesus is the Incarnation. When interpreted correctly Incarnation is one of the most nondual teachings of the Church. It says that God became human. That is what sets Christianity apart from other monotheistic faiths. But the question is: Why did God become human? According to the early church father Athanasius, it was so that humans could become God.
In the fifty-fourth chapter of his most well-known work, On the Incarnation, which he wrote when he was only as 23, he wrote this famous sentence, “God became man so that man might become God.” This teaching is known as theosis. It is the heart of the doctrine of the incarnation and therefore the heart of Christmas.