Obstacles are necessary for ...

Obstacles are necessary for success because in selling, as in all careers of importance, victory comes only after many struggles and countless defeats. Yet each struggle, each defeat, sharpens your skills and strengths, your courage and your endurance, your ability and your confidence and thus each obstacle is a comrade-in-arms forcing you to become better... or quit. Each rebuff is an opportunity to move forward; turn away from them, avoid them, and you throw away your future.
Obstacles are necessary for success because in selling, as in all careers of importance, victory comes only after many struggles and countless defeats. Yet each struggle, each defeat, sharpens your skills and strengths, your courage and your endurance, your ability and your confidence and thus each obstacle is a comrade-in-arms forcing you to become better... or quit. Each rebuff is an opportunity to move forward; turn away from them, avoid them, and you throw away your future.

Quotes from the same author

Each misfortune you encounter will carry in it the seed of tomorrows good luck.
Beginning today, treat everyone you meet as if they were going to be dead by midnight. Extend to them all the care, kindness and understanding you can muster, and do it with no thought of any reward. Your life will never be the same again.
I seek constantly to improve my manners and graces, for they are the sugar to which all are attracted.
Failure will never overtake me if my determination to succeed is strong enough.
Do all things with love.