A Christian Tradition centered around mortality?

As we discussed briefly in class on Tuesday, original sin is the attributed Augustinian belief that all of humanity, in part, take on the sin of Adam in the Garden of Eden and consequently inherited the stain of sin against God and further, death.  As Paul wrote, "sin came into the world through one man, and death came through sin, and so death spread to all because all have sinned" (Romans 5:12).  Nystrom informs us however that although it was actually Tertuilian who suggested this concept, Augustine gave original sin it's doctrinal form and therefore is attributed.
Ash Wednesday is not only a day of fasting, sacrifice and almsgiving for those who observe it, it is also a day to recognize our humanity and consequently our subjection to death. As I attended the Ash Wednesday mass at Elon Community Church last night, the priest, Fr. Gerry, highlighted this concept.  He said that when marked with the stain of ashes, we, as the congregation who observe, are reminded of our initial staining through original sin, and therefore also our mortality as a human race.  We arose from the ashes and to ashes we shall return.  Put simply, we came from the earth and we will return to the earth through death, according to this belief set.  Ash Wednesday, the important Christian tradition draws from this concept of original sin that we discussed in class.  Without this sin in the Garden, believers may be living eternally on earth without stain, without conflict, without death.
Death came through sin, as St. Augustine recognized.  Our Christian traditions and belief set concerning both the temporal world on earth and the afterlife are centered around this concept that is highlighted every Ash Wednesday.