“Son of God.” This is the first time the phrase “Son of God” is ever used of Jesus Christ, and its use in Scripture is one of the pieces of evidence that Jesus is not God and the doctrine of the Trinity is not in the Bible. The doctrine of the Trinity is that the Father is God, the Son is God, and the Holy Spirit is God, and the three of them are co-equal and co-eternal and together make up “one God;” and that Jesus is both 100% man and 100% God with both Jesus’ human and divine natures co-existing in the human body of Jesus.
God was not born, but is eternal. In contrast to the eternal God, Jesus Christ is “begotten.” Jesus had a beginning. Jesus is the “Son” of God, and children have a beginning. Although many orthodox Trinitarians say that Jesus was “eternally begotten,” that phrase is not in the Bible. It is a made-up phrase that is both nonsensical and self-contradictory. The only reason the phrase “eternally begotten,” exists at all in theological circles is that the Bible says Jesus is the Son of God, and Trinitarians assert that Jesus is eternal God, so they assert that Jesus must be “eternally begotten.” But Jesus is God’s “Son,” and nowhere in the Bible does God state the word “Son” does not have its common meaning when it comes to Jesus. In fact, the opposite is true. The angel Gabriel told Mary that God would impregnate her, and “for that reason” the child Jesus would be called “the Son of God” (Luke 1:35).
A study of the theological concept of “eternally begotten” reveals that a debate has raged for centuries about whether Jesus is in fact “the eternally begotten Son.” There are a number of Trinitarians who admit that Jesus cannot be an “eternal Son,” many of them noting that a “Son” had a beginning. However, rather than saying that there was a time Jesus did not exist, they say that Jesus existed as God, but not as the Son, before he was born of Mary. However, the Bible has no description or explanation of how that could have been. God is a spirit, so was Jesus spirit before he was human? The Bible never says. We assert that the reason that the Bible never speaks about the kind of being Jesus was before his birth is very simple: before God impregnated Mary, Jesus did not exist except in the mind of God and as part of God’s plan.
The Jews of the Old Testament never thought that their Messiah was somehow alive. The Messiah was coming in the future. Dustin Smith writes: “Jesus is certainly not alive and active anywhere within the pages of the Hebrew Bible. …In fact, the author of Hebrews argues that God used to speak through prophets, but in these last days He has spoken to us through a Son (Heb. 1:1-2) indicating that God didn’t speak through a Son in the Hebrew Bible” (Charles L. Irons, Danny A. Dixon, and Dustin R. Smith, The Son of God: Three Views on the Identity of Jesus. Wipf & Stock Publishers, Eugene, OR, 2015, p. 37. Emphasis his).
The prophecies of the Old Testament always spoke of the Messiah as one who was coming in the future, not someone who was already there. He was to be the offspring of the woman (Gen. 3:15). He would be a descendant of Abraham (Gen. 12:3; 18:18; 22:18). He would be from the tribe of Judah (Gen. 49:10). He was still far off, but a star coming out of Jacob (Num. 24:17). He would be a descendant of David (2 Sam. 7:12-13; Isa. 9:7; 11:1). He will rule over the world (Ps. 2:8; Dan. 2:44). He would be both a king and priest (Ps. 110:1-4). The Jews were well aware that God was with them, but there is no indication that any of them thought of their Messiah somehow with them too; that he was with them as some kind of spirit being, but would later come and be with them in the flesh.
The phrase Son of God is simple and straightforward. God impregnated Mary while she was still a virgin and she bore God’s son, making Jesus “the Son of God.” [For more on Jesus having a beginning, see commentary on Matthew 1:18].