Concern yourself not with ...

Concern yourself not with what you tried 
 and failed in, but with what it is still possible for you to do.
Concern yourself not with what you tried and failed in, but with what it is still possible for you to do.
 Pope John XXII

More phrases

Effort only fully releases its reward after a person refuses to quit.
Never complain and never explain.
A good plan violently executed now is better than a perfect plan executed next week.
 George S. Patton
Problems are not stop signs, they are guidelines.
 Robert Schuller
Never give up, for that is just the place and time that the tide will turn.
 Harriet Beecher Stowe

Quotes from the same author

The Saviour Himself is the door of the sheepfold: 'I am the door of the sheep.' Into this fold of Jesus Christ, no man may enter unless he be led by the Sovereign Pontiff; and only if they be united to him can men be saved, for the Roman Pontiff is the Vicar of Christ and His personal representative on earth.
 Pope John XXII