1 Corinthians 15 (Good News Translation)
21 For since death came through a man, the resurrection of the dead comes also through a man. 22 For as in Adam all die, so in Christ all will be made alive.
So, according to this Adam and Christ are opposites - and also I think opposite ends of the same era (I shall explain this later)
Thanks to Adam and his companion Eve's disobedience humankind fell and all their descendants inherited original sin
Thanks to Jesus Christ suffering on the cross humans are able to know redemption from their sins
Adam and his companion Eve brought damnation to humankind and sewed the seed of original sin
Whereas Jesus brings salvation to humankind - a way out of sin
Adam was a man who fell, Christ is a man who rose
Finally, Adam made it so that all humans eventually die. Whereas Jesus made it so that all humans can have the opportunity to enjoy eternal life. He essentially un-did the punishment that Adam and his companion Eve were responsible for.
So, basically: Adam (and his companion Eve) are responsible for humankind's fall into sin, and Jesus Christ is responsible for humankind's redemption from the consequence of sin.
After Jesus ascended into Heaven humankind entered into a new era - a new dispensation. A new relationship with God that superseded the relationship between humankind and God that had existed since the fall of humankind and up until Christ's ascension.
Therefore there was an era in human history which began with Adam and the fall and ended with Jesus and his resurrection. That era is now over, and we are in a new one, in which we can learn about Christ and relate to God through Christ The Son. And also, in which our sins may be pardoned and after which we may know salvation
That's what I think, anyway!