Is the doctrine of eternal sonship biblical? What is meant by eternal sonship?

from the old testament

• The Old Testament does not explicitly teach the doctrine of eternal Sonship, but it contains hints that point to the Son’s unique relationship with God and His preexistence. Psalm 2:7 says, “I will tell of the decree: The LORD said to me, ‘You are my Son; today I have begotten you.’” This introduces the concept of a unique Sonship that is not about ordinary human generation.
• Proverbs 8:22–30 describes Wisdom as “brought forth” by God before creation. Christian theologians often see this as a foreshadowing of the Son being eternally with the Father, active before all creation.
• Isaiah 9:6 refers to the coming Messiah as “Everlasting Father” and “Mighty God,” implying His eternal existence and a special divine identity.

from the new testament

• Jesus spoke about this eternal relationship in His prayer in John 17. He said, “You loved me before the foundation of the world” (John 17:24). This reveals that the Father and the Son already stood in a real, personal relationship before creation. Fatherly love implies Sonship, and Jesus places that father–son relationship in eternity past, long before He took on human flesh.
• The New Testament also describes the Father as sending the Son into the world. John wrote that “God did not send his Son into the world to condemn the world” (John 3:17), and Paul noted that “when the fullness of time had come, God sent forth his Son” (Galatians 4:4). In both cases, the implication is that the Son was already the Son at the moment of being sent. The One who came was not becoming the Son but was the eternal Son entering the world to accomplish redemption.
• The New Testament also presents the Son as active in creation itself. Hebrews taught that God made the world through His Son (Hebrews 1:2), and Paul wrote that all things in heaven and on earth “were created through Him and for Him” (Colossians 1:16). That God created through His Son implies that He was already His Son before creation.
• The doctrine also fits what all of Scripture says about God’s unchanging nature. For example, James taught that with God “there is no variation or shadow due to change” (James 1:17), while the author of Hebrews declared that “Jesus Christ is the same yesterday and today and forever” (Hebrews 13:8). If God does not change, then His internal relationships cannot change. In other words, the first Person did not change to become the Father at the incarnation, and the second Person did not change to become the Son in Bethlehem.

implications for today

A fire drill is more than just a break for school kids and employees. It’s the working out of a plan that was already put in place in case of emergency. Our salvation was also based on a plan, one that God had worked out before we were even born. Our salvation as Christians depends on one truth: Jesus is the eternal Son. Before the world existed, the Father had already purposed that His Son would enter the world to save sinners (Ephesians 1:4–5; 1 Peter 1:20). The Father’s plan began with His eternal love for His Son and His desire to bring redeemed people into that love. Salvation is, therefore, rooted in a relationship that did not start in time but has always existed.

That means we can depend upon it. When it seems as if the world is in chaos—violence erupting, wars going on, rampant sin—we can know that God has a plan. That plan cannot be thwarted by anyone or anything. As believers, we can rest on that, putting our anxieties on Him, trusting that He has everything under control.