"The fact that a believer is happier than a skeptic is no more to the point than the fact that a drunken man is happier than a sober one. The happiness of credulity is a cheap and dangerous quality."
George Bernard Shaw

"Man must not demolish, but build; he must raise temples where mankind may come and partake of the purest pleasure."—Goethe

"We all shine on, like the moon and the stars and the sun."—John Lennon, "Instant Karma!"

"Always changing; everything for good, nothing for nothing."—Flying Hawk, Sioux Chief

"We aim above the mark to hit the mark."—R.W. Emerson

A couple of nice quotations:

"Not knowing when the dawn will come, I open every door."—Emily Dickinson

"Our life is what our thoughts make it."—Marcus Aurelius