If we knew at what time we were to depart from this world, we would be able to select a season for pleasure and another for repentance. But God, who has promised pardon to every repentant sinner, has not promised us tomorrow. Therefore we must always dread the final day, which we can never foresee. This very day is a day of truce, a day for conversion. And yet we refuse to cry over the evil we have done! Not only do we not weep for the sins we have committed, we even add to them.
-- Saint Gregory the Great
