God’s Son is eternal, as He is. By this, we don’t mean that the Son has no cause or origin, like the Father, but that, as the Nicene Creed articulates it, “there was never a time when the Son was not”, and “there was never a time when the Father was without the Son”. That’s because the Son was begotten of the Father before and outside of time. Thus, there can be no difference in time between the persons on account of the Son’s eternal generation by the Father.
In John 1, and Proverbs 8, we see that the Son already existed at the time of creation. Scripture tells us all things were created through Him -even time itself, as Hebrews 2:1 tells us. The Son’s eternal existence is an important point of trinitarian doctrine, and something scripture emphasizes in several places.
Here a several such passages:
“In the beginning was the Word, and the Word was with God, and the Word was God. 2 He was in the beginning with God. 3 All things were made through Him, and without Him nothing was made that was made.” (John 1:1-3 NKJV)
“in these last days did speak to us in a Son, whom He appointed heir of all things, through whom also He did make the ages;” (Hebrews 1:2 YLT)
“And now, O Father, glorify Me together with Yourself, with the glory which I had with You before the world was.” (John 17:5 NKJV)
““Father, I desire that they also whom You gave Me may be with Me where I am, that they may behold My glory which You have given Me; for You loved Me before the foundation of the world.” (John 17:24 NKJV)
“The Lord acquired me in the beginning of his way, before his works of old. I was set up from everlasting, from the beginning, or ever the earth was. When there were no depths, I was brought forth; when there were no fountains abounding with water. Before the mountains were settled, before the hills was I begotten:” (Proverbs 8:22-25)
From these passages of scripture, we can clearly understand that God’s Son not only pre-existed prior to the incarnation, but that He was even with the Father before the creation of the world.
Certainly even a cursory examination of the church fathers makes clear their belief in the Son’s pre-existence before the incarnation as well. For example:
“And His Son, who alone is properly called Son, the Word who also was with Him and was begotten before the works, when at first He created and arranged all things by Him, is called Christ, in reference to His being anointed and God’s ordering all things through Him” (Justin Martyr, Second Apology, Chapter 6)
“But this Offspring, which was truly brought forth from the Father, was with the Father before all the creatures, and the Father communed with Him; even as the Scripture by Solomon has made clear, that He whom Solomon calls Wisdom, was begotten as a Beginning before all His creatures and as Offspring by God…” (Justin Martyr, Dialogue With Trypho, Chapter 62)