When Adam and Eve, or the first parents, sinned, they “died”. This means they became separated from God and lost the opportunity to receive the Divine Love, which would have given them immortality. As a result of their disobedience, the potential for immortality through the Divine Love was withdrawn from humanity and all were counted “dead in sins” till the time determined by the Father.
That time came with the birth of Jesus, who had a special relationship with God and started receiving the Divine Love from birth. In maturing, he realized that he was called to be the prophesied Messiah (anointed for a special purpose). That purpose was to proclaim the good news about the re-bestowal of the Divine Love resulting in the New Birth. It was in Jesus, that the Old Testament prophecies of the new heart and new covenant were first being fulfilled.
Metaphorically speaking, in the book of Genesis (3:22-24) Adam and Eve, because of disobedience and rejecting God’s instruction, were banished from access to the Tree of Life, which would have given them immortality. According to the book of Revelation (2:7 and 22:2, 14), access to the symbolic Tree of Life is restored.