Pre-fall refers to the condition of human nature before the fall of Adam and Eve in the garden of Eden. God made them perfect, in His image (Genesis 1:27) without any tendency to sin.
Post-fall is the direct opposite: the nature inherited after the Fall by humans due to the sin committed in Eden. It basically infers the tendecy to sin, ie, a sinful nature.
As one who has many times be caught in the crossfire between those who have a pre- or post- fall understanding of Christs nature, I have a few observations to make, and a few thoughts to suggest. And in a way, this issue connects with the Investigative Judgment debate as well.
Part of the conflict of the human nature of Christ rises from a definition of sin. To hold that Christ had a post-fall human nature, and yet is without sin, requires a definition of sin which relies on choosing to commit sin. It demands that the only acceptable definition of sin is that in 1 John 3:4 sin is the transgression of the law. Thus Christs major difference from the rest of us is that He did not break the law. Without exception (so far) those I have known who insist on the post-fall nature of Christ, also insist on this definition of sin. Above all, they cannot admit a definition of sin where it is inherited, or Christ would have been a sinner too.
It is in confronting this assertion that some have raised the question of newborn babies that die at birth are they sinners? It is the question
reductio ad absurdum which, if answered honestly, points up the validity or otherwise of this understanding. (And no, Doc, those who pose this question do not pose such questions as how many angels dance on the head of a pin you are being absurd, my friend!) If a baby is NOT a sinner, and dies at birth, then what is its need for a Saviour? I have in fact been told that such babies are innocent and saved! (Even though For all have sinned and come short of the glory of God.) If a baby IS a sinner in what way is it a sinner? The above definition, though valid in and of itself (ALL transgression of the law is indeed sin!), it is inadequate for discussing the human nature of Christ.
There are at least two other definitions of sin in Scripture. In Romans 14:23, Paul declares that whatever is not of faith is sin. And in James 4:17, Therefore to him that knoweth to do good, and doeth it not, to him it is sin. Do these definitions help?
The James definition has the same shortcoming in this context as the 1 John definition. And the Romans definition likewise does not help, for while we might agree a baby does not have faith in the Biblical sense, that would apply to Christ as a baby as well.
The nearest I can come is when I consider 2 Corinthians 5:21 (For he hath made him to be sin for us, who knew no sin; that we might be made the righteousness of God in him.), in conjunction with several other concepts. Yes, Christ bore our sin and our sins. But in what way was He made sin for us? There is only one way I can see. It derives from Isaiah 59:2 But your iniquities have separated between you and your God, and your sins have hid his face from you, that he will not hear.
Sin separates us from God. Every human being on this planet is born separated from God, and needs a reconciler, a redeemer for none is righteous, not one. How are babies sinners, in need of a Savior? By being born alienated from God. Sinning is our natural bent, because we are all, from birth, self-focused, separated from God. Behold, I was shapen in iniquity; and in sin did my mother conceive me. (Psalm 51:5). David didnt mean his mother was a prostitute he clearly meant he himself was formed in sin. True of all humankind - except Jesus.
Yes, Jesus was born with all the inherited physical weaknesses of thousands of years of sin. But of Jesus, the angel proclaimed in Luke 1:35, And the angel answered and said unto her, The Holy Ghost shall come upon thee, and the power of the Highest shall overshadow thee: therefore also that holy thing which shall be born of thee shall be called the Son of God. Note Jesus is called that holy thing a term used of no other being born on this planet. At no time from His conception was Jesus separate from the Father, until Gethsemane and Calvary.
As He assumed the weight of the guilt of the world, the sin of the world, and the Father withdrew His presence from Jesus, Christ indeed was made sin for us. No wonder He cried out, My God, my God, why hast thou forsaken me?
And here I believe is the definition of sin which can resolve this debate. Christs human nature was pre-fall IN THE SENSE THAT He was at no time separate from God. And because of this, He did not have the same tendencies to evil that we all have/develop. We have an indication of this also in Christs words in John 14:30, for the prince of this world cometh, and hath nothing in me. The devil could find nothing in Christ which would respond to him.
In all other senses, Christ has the nature of humankind after the fall.
Ill try to link this to the Investigative Judgment in another post.