The doctrine of eternal Sonship declares that the second person of the triune godhead has eternally existed as the Son. There was never a time when he was not the Son of God. At the incarnation he became a man; he did not become the Son.
Those who deny this foundational truth teach that Jesus became the Son of God at some point in history. Some say that he became the Son at his baptism; others at his resurrection. Most, however, say that he became the Son at the incarnation.
In this timely book the authors present with clarity the scriptural basis for the doctrine of the eternal Sonship of Christ, deal thoroughly with alternate views that deny this essential doctrine, and conclude with an explanation of why this truth is so vital to evangelical Christianity.

Author - George W. Zeller
Author - Renald E Showers

God's Gift of Tongues by George W. Zeller