I just wonder how many of you would answer this question. Better than that I wonder how pastors today would answer this question.
For many of us it is fairly simple explanation as we have been taught. Because Adam and Eve sinned against God everyone will have a physical death and to have ever lasting life we need to accept Jesus Christ as our redemptive savior and in doing so we have then the ability to live with Christ in Heaven throughout eternity. While this is truth it is about 1% of what humanity lost in the Garden of Eden.
At the top of the list is humanity lost its relationship with God. Humanity did not get the chance to walk with God as Adam and Eve did in the cool of the evening. In this relationship, the physical body was the house of the spiritual body which ran things. It was the spiritual body where the relationship between the physical man and God existed. No longer was that automatic. Yes God worked with Adam and Eve transitioning them out of the Garden of Eden and God's protection to residing on the earth off the mountain just like the serpent. Once this transition process was complete the relationship the rest of humanity got was through either direct conversation with God (cloud during the day and pillar of fire at night) or through the prophets or seers. Instead of having a direct relationship with God where He provided dominion over all things (the third reason of creating humanity) He walked with His people to protect them from who? The other bloodline infiltration to protect the line of Christ birth to fulfill the law of the Covenant with humanity as God amended after Adam and Eve sinned.
So people were left up to themselves to reason with themselves about the spiritual things of life. Sin had caused this to not be a direct relationship to God anymore but one that the physical mind of every human being had to engage to figure out how to get back to God.
The line from Adam all the way to Noah was ten generations. If you write out the Hebrew meaning of each of the names from Adam to Noah it forms a prophetic statement that summarizes all of scripture!
The following is the Hebrew name and the Hebrew meaning of the name from Adam to Noah.
Adam - Man
Seth - Appointed
Enosh - Mortal