Who made Adam the Federal Head?
God ordained and declared Christ the head of His church.
Holy Scripture teaches there are two "Adams." If the last Adam (Christ) is head of His
spiritual offspring, then in principle the first Adam is head of his physical offspring. If the two had not been contrasted in Scripture, then the first would not have been a type of the last. Since the first Adam is a type of Jesus Christ, who is a federal head of the Church, then the same truth and office would apply in type to the first Adam.
Where does the scripture even use that term?
It doesn't. It is a theological term used to teach an overarching principle and Truth . . like as the words "Trinity" and "Triune" are used to define and reveal the overarching principle and Truth of the Godhead.
Holding children to be guilty for the personal sins of their parent is not just, not even by God's standards.
Agreed.
On the other hand, if a parent breaks the law and takes illegal drugs the consequences might be some sort of damage to their children's brains. Such a situation would impose all kinds of dysfunctionality and might actually result in bad behavior in their children. An example of this is Fetal Alcohol Syndrome. Whether the child himself was the origin of the original sin does not change the effect his parents sins have had on his life. This is not imputed guilt but natural consequences. It is more like how the Eastern Church has always seen it.
There is a factor missing in your argument that goes beyond natural consequences: Satan's deception of Eve that led to Adam's disobedience, and the resultant curse and enslavement to Satan that occurred according to God's prophetic warning in Genesis 2:16-17, 3:14-19
Through fear of death (the ordained sentence against sin), all creation has been cursed, and held captive and controlled by Satan. This is very reason for the incarnation and High Priesthood of Christ. To free His church from this bondage. Hebrews 2:9-18; Galatians 3:10-14
Simply this. The Holy Spirit no longer indwelled humanity after the Fall. They had soul-life and physical-life but not Spiritual-life. The whole point of the cross was to restore this close communion with God through a new (Spiritual) birth. By this means the Holy Spirit could be once more united to man's spirit.
A couple of points here, where I differ.
First, I believe there was always a remnant that found salvation prior to the incarnation of Christ. There was the lineage of Abel to Noah of godly souls that called on the name of the Lord (which required regeneration and the indwelling of God's Holy Spirit . . and then Job, Abraham's lineage; Moses, King David, the prophets, etc.
I am not sure it is correct to claim that the Holy Spirit "unites" with the human spirit, but rather reveals His presence as indwelling the bodily temples of redeemed men/women. Why? The word used to describe this indwelling is "abide." e.g. John 15:4 Does that word mean "unite" in the Greek? I do not know . . .
If Christ had not been born of a virgin he would have been in the same shape as all other people. He could not have been a perfect sacrifice because He would have become a sinner like all men inevitably do. Because he was through Mary related to the human race He could represent us. However as an unfallen Son of God He could also represent God. Thus he was the perfect mediator.
Amen!
He was also a ransom to pay the consequences of sin on our behalf. I do not believe this ransom was paid to God. The Bible says the Devil (who had the power of death) is the one who crucified Jesus. In that act and in the subsequent resurrection Jesus broke the power of death, the Devil and sin.
Agreed, but I see the ransom as a debt owed to God, not the devil.
Christ's sacrifice indeed broke and freed souls from the power of death, as I touched on above, but I believe the ransom or debt of sin was paid by Christ on the cross, offering Himself, for Himself as representative of His church, in the offices of both Savior and High Priest. IOW's God paid God the price to redeem His church. I Peter 1:18-19; Acts 20:28