What does God from God Light from Light true God from true God mean?

Answer 1

"God from God, Light from Light, True God from True God" is a formulation of the Nicene Creed of 325 which is intended to refute the heresy of Arianism-- the proposition that Jesus Christ was not true God from all eternity, but instead was created. Indeed, Jesus Christ is of one substance (homousios) with God the Father, such that he is completely God as God the Father is, he is completely Light as God the Father is Light, he is True God as God the Father is. In the articles of faith regarding Jesus Christ, the Nicene Creed skillfully refutes excesses in both the Alexandrian and the Antiochene Christological schools which stress the divinity of Christ on one hand, and the humanity of Christ on the other. The resulting tension in the orthodox understanding of the relationship between the divinity and humanity of Christ is described as the 'hypostatic union'. In the councils between the first and fifth centuries, these doctrines were defined and are held by all orthodox Christians today (Catholics, Orthodox, and most Protestants). Mind you that doctrines are not being created ex nihilo at councils, but rather are being formulated as definitive teaching from the living experience of the Church in response to a challenge or crisis. The "Council of Jerusalem" described in Acts 15 sets not just the precedent for such a meeting, but essentially sets the model of the apostles (bishops) of the Church coming together under the power of the Holy Spirit to solve the problems and challenges of the particular age. In this, we find further support for the notion that the Church is a living entity (the "Mystical Body of Christ"), rather than a simple social or political institution. Further, such meetings underscore how Divine Revelation is a product of both scriptural reflection, as well as the product of Sacred Tradition held within the Church.