We believe in one Lord, Jesus Christ, the only Son of God, eternally begotten of the Father, God from God, Light from Light, true God from true God, begotten not made, one in being with the Father. Through Him all things were made. For us men and for our salvation, he came down from heaven.
This part of the Creed is about Jesus, the second person of the Trinity. Just as we believe in only one God the Father, we believe in only one God the Son, who is called Jesus Christ. Even his name tells us who he is and why he came to us. “Lord” is used in the Old Testament to tell us that God is divine. In the New Testament, the title is used for both the Father and Son, stressing that we recognize Jesus as God himself. Jesus means “God saves” in Hebrew and Christ is a Greek translation of Messiah, which is “anointed” in Hebrew. There is only one Son, who comes from the Father, and has existed since the beginning of time. The words “true God from true God” remind us that Jesus was both fully divine and fully human. His incarnation, when “he came down from heaven,” did not make him less divine, but rather he has both his divine and human nature. The two natures cooperate so that his human will is obedient to the Father so that we would have eternal salvation. Jesus’ incarnation gives dignity to the human person and leads us to share in his divinity.
As we pray these words each Sunday, recall how Jesus humbled himself to become like us and then saved us. When we do that, gratitude is our response.
For more in-depth information see the Catechism of the Catholic Church, paragraph 422 to 483, (Part 1, Section 2, Chapter 2)