Well, I believe Christ's soul was 100% divine and that the body was an outward shell or temple. I believe Christ suppressed His divine power of Omniscience (i.e. To have all knowledge) so as to be like a man. Hence, why He said that He did not know the day or hour of His own return (Matthew 24:36), and hence, why He was able to grow in wisdom (Luke 2:52). Yet, Jesus still was God on the inside 100%. The Living Word (second person of the eternal Trinity) did not join with a human soul, or mind and nor was a new human soul created tailored made for Him. Christ has always had His own mind and soul that is eternal. 1 John 4:3 says Jesus Christ was manifested in the flesh. This means Jesus (the Living Word) came down into the flesh of a man (or a human body suit).
I have discussed this issue many times, and I have yet to have anyone show me a specific verse or passage saying how Jesus clearly joined with a human soul or that a human soul was added to His divine soul. Jesus only has One soul and it is 100% divine and eternal. The body was just a shell or temple. Note: Others have suggested Colossians 1:19 and Colossians 2:9. This implies the fulness of the Trinity was in him (a human soul), but it doesn't exactly say "human soul;" It could easily be referring to the Logos (the Word) while dwelling in the flesh.
Jesus also said to the Pharisees that He had seen Abraham, and they mocked him for it in John 8. Yet, if Jesus was a new creation, He could not really make this claim.
Many fail to understand what a soul is. A soul is one's mind, will, and emotions. Surely Jesus did not join with a brand new mind, will, and emotions that were human, thus being a new being or creation within the universe. No Scripture verse reveals that kind of thing. On the contrary, Scripture suggests that the Messiah was not a newly created being in the universe, but He has always existed.
"But thou, Bethlehem Ephratah, though thou be little among the thousands of Judah, yet out of thee shall he come forth unto me that is to be ruler in Israel; whose goings forth have been from of old, from everlasting." (Micah 5:2).
Another thing people fail to understand is that Jesus had power during His Earthly ministry, too.
#1. Jesus said He has power to raise the dead to life just as the Father had power to raise the dead (John 5:21).
#2. Hebrews 1:3 talks about how Christ held all things together by the word of His power when He purged us of our sins.
#3. Jesus said, He would raise up this Temple (His body) three days later (John 2:19).
#4. Jesus had the power to forgive sins and give eternal life (Mark 2:7) (Luke 7:44-50) (John 14:6).
#5 Jesus had power to take away the sins of the entire world (John 1:29).
#6. Jesus Christ said wherever two or three are gathered in my name, there I am among them (Matthew 18:20). This was said to the people he was around and not to just us today.
#7. Jesus knew men's thoughts (Matthew 9:4) (Matthew 12:25) (Mark 2:8) (Luke 5:22) (Luke 6:8) (Luke 9:47) (Luke 24:38).
#8. Jesus knew about the lives of others (John 2:24) (John 4:17-18) (John 4:29) (John 6:64).
