Divine filiation
Divine filiation is the Christian doctrine that Jesus Christ is the only-begotten Son of God by nature, and when Christians are redeemed by Jesus they become sons (and daughters) of God by adoption. This doctrine is held by most Christians.
Divine filiation builds on other Christians doctrines. In the doctrine of the Trinity, God the Son is the Eternal Word spoken by God the Father. The doctrine of the Incarnation teaches that around 2000 years ago, God the Son assumed a human nature, "became flesh and dwelt among us" (John 1:14) as Jesus of Nazareth.
Divine filiation is the centerpiece of the Gospel, the Good News: it is the reason why humanity was saved. And is also the purpose behind baptism. According to John Paul II, divine filiation is "the deepest mystery of the Christian vocation" and "the culminating point of the mystery of our Christian life...we share in salvation, which is not only the deliverance from evil, but is first of all the fullness of good: of the supreme good of the sonship of God."