What defines our lives is not what we have been, miserable sinners, but what we shall be at the end, children of God, renewed in the perfect image of Christ.
There are two ways of going through life, one with our lives being defined by what we have done, and from the point we come from, which is sin, the other by the end to which we have been appointed by God's mercy, by the victory Christ won for us that will be fully manifested in the future, a new and renewed life, citizenship in heaven.
That is the defining factor of our existence because that is the reality which will endure forever.
... Although we cannot ignore the past, its failures do not define us any more. ....
That is why whoever embraces this hope, who ever learns to live according to it, changes his relationship with sin, and with his past. Sin is not the master anymore. Our past does not hinder us, Sin is 'left behind', while we continue walking by faith, in hope purifying ourselves as he is pure, renouncing more and more our sins.
Thank you, Sionnsar, for the ping. This is well put! Sadly, not very many christians live this kind of life because they are not being tought this truth. If more of us lived as though Glory were really our tomorrow, this world could not contain the contagion. Our challenge as followers of Christ is to spread this good news to every creature.