A promise is meaningless if it isn't kept. If you promise something that you find that you cannot do -- then go to the person you promised and admit that you are going to fail and apologize.
Faithfulness and loyalty are two of the virtues that separate the run of men from those seeking to be better. Robert Browning said: "A man's reach should exceed his grasp, else what's a heaven for." So keep your promises, even if it is difficult, and you will gain the respect and trust of others. --RaySchneider
Matthew 5:33 “You have also heard that our ancestors were told, ‘You must not break your vows; you must carry out the vows you make to the LORD.’o 34But I say, do not make any vows! Do not say, ‘By heaven!’ because heaven is God’s throne. 35And do not say, ‘By the earth!’ because the earth is his footstool. And do not say, ‘By Jerusalem!’ for Jerusalem is the city of the great King. 36Do not even say, ‘By my head!’ for you can’t turn one hair white or black. 37Just say a simple, ‘Yes, I will,’ or ‘No, I won’t.’ Anything beyond this is from the evil one." I might suggest that one always do what one says, even if not a promise; and if you cannot carry out both the spirit and the letter of your word "-- then go to the person you spoke with and admit that you are going to fail and apologize." -- ErikMcCarty