We read, "For the trumpet will sound and the dead will be raised!" This is the promise!
We might question the Catholic doctrine of the Assumption of Mary, which is celebrated on this date, but it is pretty hard to question the number of appearances that have been attributed to Mary.
Whether it was at Lourdes, Fatima, Guadalupe or Medjugorje, people attest to seeing her. This tells me that the promise has been fulfilled in her and will be fulfilled in us.
There have been other documented appearances by others who have died. I believe that these appearances are blessings from God to reassure us that Jesus promise of eternal life and the resurrection of the body is true. It is something we can rely on.
Paul is letting us know that the gift of immortality is for all. Death is the result of sin, and as we all sin, we all die. The original intent was for humanity to be immortal, but sin entered the world and the natural order that God intended was upset.
Because it would be impossible for us to save ourselves, it became necessary for a redeemer. Jesus came so that the natural order could be restored. Through his death and resurrection, we are saved.
Through his life, we know how to live so as to receive the promise. We do this by accepting the gift of faith and living lives of love.
Mary accepted the responsibility of becoming the Mother of God, Jesus, our Savior.
When we were baptized, we accepted the responsibility of following the path that Jesus took. We accepted the mission of a disciple; that of caring for the poor and the vulnerable and working for justice.
The reward is immortality.

