St .Paul, writing in his second letter to the Corinthians, tells his readers that, "Now is the acceptable time, now is the time of salvation."  He is urging them forward in their faith so that it may not be received "in vain".  The Dominican St. Albert the Great (d. 1280), in his homily on this text, emphasizes this urgency:

"We should perform good works now because of the shortness of the time.  When someone has something to do and he has a lot of time in which to do it, it is no surprise if he should sleep for a long time.  But if a traveler has a long journey to make and he does not have enough time, and he is wise, and he wishes to come to a good lodging before the gates close, he rushes upon his journey early in the morning.  So, if we were to live for a long time, and we knew this, then it would be small wonder if some should tarry in sin for a long time, and put off doing well.  But we have a long journey to make -- to heaven.  3 Kings 9, 7: 'You have yet a great way to go.'  And there is not enough time, for, 'the days of a man are short' (Job 14, 5).  Thus, we must start the journey quickly.  We start the journey for heaven when we leave our sins behind us and begin to perform good works.  1 Corinthians 7, 29: 'Therefore I say this to you, brothers: the time is short.'  It is a wonder that sinners promise themselves a long life more than the good do, when it ought to be the other way around.  If anyone has a fruit-bearing tree in his garden, and another tree that does not bear fruit, he would cut down the latter sooner than the former.  The wicked whom God permits to dwell in this world for many years ought to fear, for God is waiting for their fruit, and if they do not bear any, they will be quickly uprooted.  Luke 13, 7, on the fig tree: 'Behold, for three years I have come seeking fruit on this fig tree, and I have not found it.  Cut it down.  Why should it take up the land?'  We, who are terrible sinners, have only a little time, and we are not free from danger, so we should not delay to do well.  Galatians 6, 10: 'While we have time, let us do good for all.' "