"When you reach the end of your rope, tie a knot in it and hang on." 
-Thomas Jefferson

"Patience is not passive; on the contrary, it is active; it is concentrated strength."
-Edward G. Bulwer-Lytton

“Feel like Christ and you will be a Christ; feel like Buddha and you will be a Buddha. It is feeling that is the life, the strength, the vitality, without which no amount of intellectual activity can reach God.” 

-Swami Vivekananda 

"Give us grace and strength to forbear and to persevere. Give us courage and gaiety and the quiet mind, spare to us our friends, soften to us our enemies." 

-Robert Louis Stevenson