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

"It is always the false that makes you suffer, the false desires and fears, the false values and ideas, the false relationships between people. Abandon the false and you are free of pain; truth makes happy, truth liberates." 

-Nisargadatta Maharaj

"There is no coming to consciousness without pain. People will do anything, no matter how absurd, in order to avoid facing their own soul. One does not become enlightened by imagining figures of light, but by making the darkness conscious." 

-Carl Jung

"If you are distressed by anything external, the pain is not due to the thing itself but your own estimate of it; and this you have the power to revoke at any moment." 

-Marcus Aurelius Antoninus Augustus

“We can never judge the lives of others, because each person knows only their own pain and renunciation. It's one thing to feel that you are on the right path, but it's another to think that yours is the only path.” 
-Paulo Coehlo

"Pain is inevitable. Suffering is optional." 
-Sheng Ts'an

"We cannot be more sensitive to pleasure without being more sensitive to pain." 

-Alan Watts