Nevertheless death reigned from Adam until Moses, even over those who had not sinned in the likeness of the offense of Adam, who is a type of Him who was to come.Romans 5:14(NASB)
Adam was the federal head of the whole human race, and death prevailed because of his one sin. Due to Adam's single transgression all mankind was placed under condemnation, and death, which became the just reward for all - Adam's sin caused the fall of humanity and sin and death was imputed to mankind.
God did not give His perfect Law to Israel until many centuries later, which from its establishment was a school-master to point us to Christ. And yet from the time of Adam to the Law of Moses, the icy fingers of death reigned in the lives of humanity - because Adam's sin was imputed to all, and death reigned from that point on, as a result of that one man's sin.
Many think this act of God to be unjust and unfair. Many consider that the imputed sin nature, condemnation and death.. that was inflicted upon all humanity from the time of Adam to the time of Moses was undeserved - because death reigned in the lives of everyone.. even those who did not disobey an explicit commandment of God. But this first man, Adam, was a type of the Second Man, Christ - Who was to come.
God's wisdom and ways are perfect and far beyond our limited understanding. God knew that sinful man and his fallen prodigy was far beyond the capacity to act justly, love mercy, walk humbly and live in utter dependence upon God, in their own strength.. and so in His great wisdom God purposed that a second Man would become the last Adam - Whose righteousness would be imputed upon all who believe on His name.
By condemning the whole race because of the transgression of one man.. (the first man / the first Adam - who was a type of the Man Christ Jesus), God was enabled to save and redeem the whole of humanity through of the obedience and righteousness of One Man.. (the Second Man - the Last Adam).
The first man was of the dust of the earth; the second man is of heaven, and is today seated on the right hand of the Father in power and great glory. And whoever believes on the name of the only begotten Son of God, will be saved.
Heavenly Father, thank You that in Your grace and mercy, wisdom and strength.. You purposed that Christ would come as the Second Man and Last Adam.. to save us from our sins and to give us His heavenly life, so that He may live His heavenly life through us.. to His praise and glory. We thank You on Jesus name, AMEN.