I've deduced that adam and eve died only because of sin. and this sin was eventually forgiven by god's son, jesus christ by his act on the cross.
So technically all that believe in jesus, follow him, and accept his gift of eternal life here will have eternal life.
Many christians I talk to say this eternal life does not apply on earth, but if it didn't why did adam and eve live longer than 120 years, and why didn't jesus die and rise again in the first place?
He took away the power of death from the devil.