The answer is: the life of this one man would have to be of infinite value.
How could an ordinary human being have a life of infinite value? He would have to originate before all other things and be the source of all that exists. This is precisely what we find in Jesus. He existed before anything else was created, and He is the source of all things which exist.
John 1:3 All things were made through Jesus, and without Him nothing was made that was made.
Colossians 1:16 For by Jesus all things were created that are in heaven and that are on earth, visible and invisible, whether thrones or dominions or principalities or powers. All things were created through Him and for Him.
What does Isaiah’s prophecy speak of?
Isaiah 7:14 Therefore the Lord Himself will give you a sign: Behold, the virgin shall conceive and bear a Son, and shall call His name Immanuel.
The results of this virgin birth is that the one who is born will be Immanuel, in Hebrew: God with us. The one born of a virgin, will be a man, He will also be God living with us. This is the answer to the riddle, “how can one life pay for the lives of all men?” If the life that is given is the eternal Son of God, then His life has more than enough value to pay for the lives of all other men.
Only Jesus is the Eternal Son of God, who was born of a Virgin, and lived a perfect and sinless life. He offered this perfect life as the payment for the sins of all human beings. There is no other person in the history of mankind who can make this claim, other than Jesus Christ. He is therefore, the Messiah, the Savior of all people.
This is the object of this first of 365 Old Testament prophecies. This book begins with an amazing prediction that seems impossible, and ends with the final prophecy that confirms the arrival of the One who God promised to send—who will save us from our sins.
Up until Adam’s sin, he was morally perfect. From the moment that sin entered Adam—it would permeate the entire human race and the curse of death would be upon all the descendants of Adam. One of the most profound proofs for the existence of God is the fact that sin and death exist—just as God has described them in the Bible. In Genesis chapter three, we see how sin began and the immediate response by our loving God, to put away sin and make a provision to redeem us all.
Sin and death are two curses that every human being fears and recognizes as unnatural. All of us have a deep inner sense that death is abnormal and should not occur. The fact that God describes both sin and death in the Bible—precisely as they exist in reality, is evidence that the Old and New Testament Scriptures are true. Everything that God declares about sin and the horrible consequences that come as a result of this curse is observable in the world today. The Bible is the only book in the world today that tells us the truth about the human condition.
There is a fatal flaw in human beings and all of us are aware of this defect as we observe it in ourselves and others. We have moments of intrinsic goodness, but the greater part of our lives are plagued by a constant tendency towards wrongful actions that hurt and destroy ourselves and the lives of those around us.
Incredibly, God already knew the course that Adam would take when He created him. As stated previously, the New Testament describes Jesus as: The Lamb slain from the foundation of the world. This means that before the earth was created, God had determined that He would create mankind. The first man would chose to reject God’s right of rulership and sin against Him. This action would require a Redeemer to save us.
Jesus offered Himself as the Savior, before the world was made. For this reason, He is forever called; The Lamb slain from the foundation of the world.
Revelation 13:8 …the Book of Life of the Lamb slain from the foundation of the world.
Jesus volunteered in eternity, to be the fail-safe plan for man when he sinned and condemned himself to an eternal death, even before Adam breathed his first breath.
See the following articles: The “Almah” of Isaiah 7:14, is a Virgin If Jesus was not Born of a Virgin, He Could not be our Savior