Time

Here's a great quote (courtesy of The Hermeneutic of Continuity) from one of my favourite saints (St. Alphonsus de Liguori):

"St Bernadine of declared that a moment of time is of as much value as God; because in each moment a man may, by an act of contrition or of love, gain Divine grace and eternal glory. [...] Time is a treasure which is found only in this life; it is not to be found in the next, neither in hell nor in heaven. In hell, the lamentation of the damned is O, si daretur hora! - Oh, that an hour were given us! They would pay any price for one hour of time to redeem the past; but never will they have this hour. In heaven there is no weeping; but if the blessed could weep. their tears would only be shed for having in this life lost time, in which they might have acquired greater glory, and because this time they can never again possess."