Question of the Week: What would be your main, brief argument against a Unitarian who would say that Jesus did not preexist his conception and birth on Earth?
My Answer: Not all Unitarians believe that the Bible is the inspired, inerrant Word of God. For those that do I would offer the following brief response:
According to Colossians 2:9 all the fullness of the Deity dwells in Christ in bodily form. God the Father is spirit. God the Holy Spirit is spirit. The only member of the triune godhead who has a body is God the Son. Hence, when God appeared in bodily form in the Old Testament, it was God the Son. The New Testament declares that God the Son created the universe and that he existed before anything at all was created. These biblical texts imply that Jesus is an uncreated being. Therefore, he is eternal, one who has always existed.