Every person should have two slips of paper in his pocket.
On one should be written: “The world was created for me,” and on the other: “I am but dust and ashes.”
A person has to have the wisdom to read each slip in the proper time.
~ R’ Simcha Bunim of Parshischo zt”l in Simchas Yisroel
Emuna Daily 
Can locations in the various seforim be provided when available?
I will try when available, but i find many of these quoted in other seforim which are certainly reliable, but not specific.